The Hacker's Encyclopedia 1998/hackers_encyclopedia.iso/pc/virus/vsum9105.txt

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                         VIRUS INFORMATION SUMMARY LIST
                                  May 15, 1991

      Copyright (C) 1990-1991 by Patricia M. Hoffman. All Rights Reserved.

     This document contains the compiled information from a continuing
 research effort by the author into the identification, detection and
 removal of MS-DOS Computer Viruses.  Hopefully, this listing will
 provide some assistance to those who wish to know more about a particular
 computer virus.  It is not intended to provide a very detailed technical
 description, but to allow the reader to understand what a virus
 generally does, how it activates, what it is doing to their system, and
 most importantly, how to get rid of it.

     The user of this listing needs to keep in mind that the
 information provided is up-to-date only to the date of the listing
 itself.  If the listing is one month old, some items may not be
 accurate.  Also, with the wide dispersion of researchers and the
 various names that the same virus may be known by, some of the
 information may not be entirely accurate.  Lastly, as new variants
 of known viruses are isolated, some of the characteristics of the
 variant may be different.

     There are five sections to the listing.  The first section is
 an introduction which explains the format of the information in
 the listing and includes the code information used in some fields.
 The second section is the actual virus information listing.
 The third section is a cross-reference of common names for MS-DOS
 computer viruses and indicates what name to use for the virus in the
 second section.  The fourth section, added with the July 1990 release
 and in the works for many months, is a chart showing relationships
 between various viruses and variants.  Lastly, there is a fifth section
 which is a revision history of the listing.

     Anti-Viral products mentioned in the listing are either commonly
 available shareware or public domain programs, or they are commercial
 products which have been submitted for evaluation and review by the product's
 author with "no strings attached".  All Anti-Viral products are reviewed at
 the most recent release level available to the author.  In some cases, this
 may not be the most recent release.  All testing is done against the author's
 virus collection, results using a different collection of viruses and
 variants may differ.

     Special thanks go to John McAfee for reviewing the listing before
 it is distributed, and to numerous others who have sent their comments,
 suggestions, and encouraging support.

     The Virus Information Summary List may not be used in a business,
 corporation, organization, government, or agency environment without
 a negotiated site license.  While this document may be referenced in the
 documentation for some anti-viral products, the document is not to be
 construed as being included in any site license not negotiated with
 the author, Patricia M. Hoffman, or an authorized agent of the author.
 Likewise, this listing, in whole or in part, may not be including in any
 program, magazine article, listing, or other published work without express
 written permission from the author.

     Licensing information for the Virus Information Summary List can be
 requested from the author via US Mail from the address, or by voice or FAX
 at the phone numbers below:

           Patricia M. Hoffman
           1556 Halford Avenue, #127
           Santa Clara, CA 95051
           Voice: 1-408-246-3915
           FAX  : [phone]

     The VSUMAGTS.TXT file included with the Virus Information Summary List
 contains a complete listing of domestic and international agents whom have
 been authorized to provide sales, service, and support of this listing.

     I can also be reached through my Bulletin Board System, Excalibur! BBS,
 at 1-408-244-0813.  Future versions of this listing may also be obtained
 through Excalibur!.

                                           Patricia M. Hoffman
-------------------------------------------------------------------------------
                         Virus Information Summary List
                          Introduction & Entry Format

     Each of the entries in the list consists of several fields.
 Below is a brief description of what is indicated in each of the
 fields.  For fields where codes may appear, the meaning of each
 code in indicated.

 Virus Name: Field contains one of the more common names for the
             virus.  The listing is alphabetized based on this
             field.
 Aliases:    Other names that the same virus may be referred to by.
             These names are aliases or A.K.A.'s.
 V Status:   This field contains one of the following values which indicate
             how common the virus is in the public domain.
             Common: The virus is one of the most common viruses reported to
                  various groups which gather virus infection statistics.
                  Most of these groups are in the United States.  Where a
                  virus has had many reports from a specific geographic area,
                  the V Status field will contain "Common - xxxxxxxxx" where
                  xxxxxxxxx is an indicator of geographic location.
             Endangered: The "Endangered" classification of viruses are
                  viruses that are very uncommon and were fairly recently
                  discovered or isolated.  Due to some characteristics of
                  these viruses, it is highly unlikely that they will ever
                  become a widespread problem.  It doesn't mean that they
                  don't exist, just that the probability of someone getting
                  these viruses is fairly low.
             Extinct: The "Extinct" classification is for viruses which at
                  one time may have been widespread (ie. they are not a
                  research virus which was never released into the public
                  domain), but have not had a reported infection in at least
                  one year.  "Extinct" viruses will also include "viruses"
                  which were submitted which actually don't replicate due to
                  a flaw in their viral code, but if the flaw were corrected
                  they might be successful.  It is still possible that someone
                  could become infected with one of these viruses, but the
                  probability is extremely low.
             Myth: "Myth" viruses are viruses which have been discussed among
                  various groups for some time (in excess of one year), but are
                  not known to actually exist as either a public domain or
                  research virus.  Probably the best case of a "Myth" virus
                  is the Nichols Virus.
             Rare: "Rare" viruses are viruses which were recently (within the
                  last year) isolated but which do not appear to be widespread.
                  These viruses, as a general rule, will be viruses which
                  have characteristics that would make them a possible
                  future problem.  "Rare" viruses have a higher probability
                  of someone becoming infected than Endangered or Extinct
                  viruses, but are much less likely to be found than a
                  "Common" virus.
             Research: A "Research" virus is a virus which was originally
                  received by at least one anti-viral researcher directly
                  from its source or author.  These viruses are not known
                  to have been released into the public domain, so they are
                  highly unlikely to be detected on computer systems other
                  than researchers.
             Rumored: The "Rumored" virus classification are for viruses
                  which the author has received information about, but that
                  no sample of the virus has been made available for analysis.
                  Any viruses in this classification should be considered with
                  a grain of salt, they may not actually exist.
             Unknown: The "Unknown" classification is for those viruses where
                  the original submission of the virus to anti-viral researchers
                  is suspect for any number of reasons, or that there is
                  very little information known about the origin of the
                  virus.
             New: The "New" category is for viruses which were recently
                  received by the author but cannot at the present time be
                  researched in depth.  Instead of leaving these viruses out
                  of the listing all together, they will be listed but with
                  a "New" status.
 Discovery:  First recorded discovery date.
 Origin:     Author/country of origin
 Symptoms:   Changes to system that may be noticed by users: messages,
             growth in files, TSRs/ Resident TOM (change in CHKDSK
             return), BSC - boot sector change (may require cold boot
             from known-good protected floppy to find), corruption of
             system or files, frequent re-boots, slowdowns.
 Origin:     Either credited or assumed to be in country of discovery.
 Eff Length: The length of the viral code after it has infected
             a program or system component.  For boot-sector infectors,
             the length is indicated as N/A, for not applicable.
 Type Code:  The type codes indicated for a virus indicate general
             behavior characteristics.  Following the type code(s) is
             a brief text description.  The type codes used are:
             A = Infects all program files (COM & EXE)
             B = Boot virus
             C = Infects COM files only
             D = Infects DOS boot sector on hard disk
             E = Infects EXE files only
             F = Floppy (360K) only
             K = Infects COMMAND.COM
             M = Infects Master boot sector on hard disk
             N = Non-resident (in memory)
             O = Overwriting virus
             P = Parasitic virus
             R = Resident (in memory)
               (below 640k - segment A000)
                 a - in unused portion of allocated memory
                     (does not change free memory, such as virus resident
                      in CLI stack space or unused system memory)
                     Example: LeHigh
                 f - in free (user) memory below TOM
                     (does not prevent overwriting)
                     Example: Icelandic
                 h - in high memory but below TOM
                     (Resides in high system memory, right below TOM.
                     Memory is allocated so it won't be accidently
                     overwritten.)
                     Example: Flash
                 s - in low (system/TSR) memory
                     (reduces free memory, typically uses a normal
                     Int 21/Int 28 TSR)
                     Example: Jerusalem
                 t - above TOM but below 640k (moves Int 12 return)
                     (Reduces total memory size and free memory)
                     Example: Pakistani Brain
               (above 640k)
                 b - in BIOS/Video/Shadow RAM area (segment A000 - FFFF)
                 e - in extended/expanded memory (above 1 Meg)
             S = Spawning or companion file virus
                 (This type of virus creates another file on the disk which
                 contains the actual viral code.  Example: Aids II)
             T = Manipulation of the File Allocation Table (FAT)
             X = Manipulation/Infection of the Partition Table
 Detection Method:
             This entry indicates how to determine if a program or
             system has been infected by the virus.  Where the virus
             can be detected with a shareware, public domain, or
             readily available commercial program, it is indicated.
             Note that a "+" after the anti-viral product's version number
             indicates that versions of the product from the indicated version
             forward are applicable.
             Programs referenced in the listing are:
             AVTK      - Dr. Solomon's Anti-Virus Toolkit <commercial>
             F-PROT    - Fridrik Skulason's F-Prot detector/disinfector
             IBM Scan  - IBM's Virus Scanning Program <commercial>
             NAV       - Norton AntiVirus <commercial>
             Pro-Scan  - McAfee Associates' Pro-Scan Program <commercial>
             VirexPC   - MicroCom's VirexPC Program <commercial>
             VirHunt   - Digital Dispatch Inc's VirHunt Program <commercial>
             ViruScan  - McAfee Associates' ViruScan Program
             ViruScan/X- McAfee Associates' ViruScan Program with /X switch
 Removal Instructions:
             Brief instructions on how to remove the virus.  Where
             a shareware, public domain, or readily available
             commercial program is available which will remove the
             virus, it is indicated.  Programs referenced in the
             listing are:
             AntiCrim  - Jan Terpstra's AntiCrime program
             CleanUp  -  John McAfee's CleanUp universal virus
                         disinfector.
                         Note: CleanUp is only indicated for a virus
                         if it will disinfect the file, rather than
                         delete the infected file.
             DOS COPY  - Use the DOS COPY command to copy files from
                         infected non-bootable disks to newly formatted,
                         uninfected disks.  Note: do NOT use the
                         DOS DISKCOPY command on boot sector infected
                         disks, or the new disk will also be infected!
             DOS SYS   - Use the DOS SYS command to overwrite the boot
                         sector on infected hard disks or diskettes.
                         Be sure you power down the system first, and
                         boot from a write protected master diskette,
                         or the SYS command will copy the infected
                         boot sector.
             F-PROT    - Fridrik Skulason's F-Prot detector/disinfector,
                         Version 1.07.
             M-3066    - Traceback virus disinfector.
             MDisk     - MD Boot Virus Disinfector.  Be sure to use the
                         program which corresponds to your DOS release.
             NAV       - Norton AntiVirus
             Pro-Scan  - Pro-Scan Virus Identifier/Disinfector.
             Saturday  - European generic Jerusalem virus disinfector.
             Scan/D    - ViruScan run with the /D option.
             Scan/D/A  - ViruScan run with the /D /A options.
             Scan/D/X  - ViruScan run with the /D /X options.
             UnVirus   - Yuval Rakavy's disinfector for Brain, Jerusalem,
                         Ping Pong, Ping Pong-B, Typo Boot, Suriv 1.01,
                         Suriv 2.01, and Suriv 3.00 viruses.
             VirexPC   - MicroCom's VirexPC Detector/Disinfector
                         Note: VirexPC is only indicated if it will actually
                         disinfect the virus, not just delete the infected
                         file.
             VirHunt   - Digital Dispatch Inc's VirHunt Detector/Disinfector
                         Note: VirHunt is only indicated if it will actually
                         disinfect the virus on all major variants.
             Virus Buster - Yuval Tal's Virus Buster Detector/Disinfector
 General Comments:
             This field includes other information about the virus,
             including but not limited to: historical information,
             possible origin, possible damage the virus may cause,
             and activation criteria.


-------------------------------------------------------------------------------

                         Virus Information Summary List
                            MS-DOS Virus Information


 Virus Name:  382 Recovery Virus
 Aliases:     382
 V Status:    Rare
 Discovery:   July, 1990
 Symptoms:    first 382 bytes of .COM files overwritten, system hangs,
              spurious characters on system display, disk drive spinning
 Origin:      Taiwan
 Eff Length:  N/A
 Type Code:   ONAK - Overwriting Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The 382 Recovery Virus was isolated in July 1990 in Taiwan.  It is
       a non-resident generic infector of .COM and .EXE files, including
       COMMAND.COM.

       Each time a program infected with the 382 Recovery Virus is executed,
       the virus will check the current directory for a .COM files that has
       not been infected with the virus.  If it finds an uninfected .COM
       file, it will infect it.  If the original file was less than 382 bytes
       in length, the infected file will now be 382 bytes in length.  Files
       which were originally greater than 382 bytes in length will not show
       any increase in length.  Infected files always have the first 382
       bytes of the file overwritten to contain the virus's code.

       Once all .COM files in the current directory are infected, the next
       time an infected .COM file is executed the virus will rename all .EXE
       files to .COM files.  These renamed files, however, may or may not
       later become infected.

       Symptoms of the 382 Recovery Virus being present on a file are that
       the program will not execute properly.  In some cases, the program will
       hang upon execution requiring the system to be rebooted.  In other
       cases, spurious characters will appear on the system display and the
       program will not run.  Lastly, the system may do nothing but leave the
       disk drive spinning, requiring the system to be powered off and
       rebooted.

       Since the first 382 bytes of infected files have been overwritten,
       the infected files cannot be recovered.  The original 382 bytes of
       the file are permanently lost.  Infected files should be deleted or
       erased and replaced with backup copies known to be free of infection.


 Virus Name:  405
 Aliases:     Hammelburg
 V Status:    Extinct
 Discovery:   1987
 Symptoms:    .COM files fail to run, first 405 bytes of .COM files
              overwritten
 Origin:      Austria or Germany
 Eff Length:  N/A
 Type Code:   ONC - Overwriting Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan 1.4+,
              VirexPC 1.1+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, F-Prot, NAV, or delete infected files
 General Comments:
       The 405 virus is an overwriting virus which infects only .COM
       files in the current directory.  If the length of the .COM file
       was originally less than 405 bytes, the resulting infected file
       will have a length of 405 bytes.  This virus currently cannot
       recognize .COM files that are already infected, so it will
       attempt to infect them again.

       The 405 Virus doesn't carry an activation date, and doesn't do
       anything but replicate in the current directory.  However, since
       it overwrites the first 405 bytes of .COM files, infected files
       are not recoverable except by replacing them from uninfected
       backups or master distribution disks.


 Virus Name:  512
 Aliases:     512-A, Number of the Beast Virus, Stealth Virus
 V Status:    Rare
 Discovery:   November, 1989
 Origin:      Bulgaria
 Symptoms:    Program crashes, system hangs, TSR.
 Eff Length:  512 Bytes
 Type Code:   PRCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V58+, VirexPC 1.1+, IBM Scan 2.00+
 Removal Instructions: CleanUp V58+
 General Comments:
       The 512 virus is not the same as the Original Friday The 13th COM
       virus.  The 512 virus was originally isolated in Bulgaria in
       November, 1989, by Vesselin Bontchev.  It infects .COM files,
       including COMMAND.COM, installing itself memory resident when the
       first infected program is run.  After becoming memory resident, any
       .COM file openned for any reason will become infected if its
       uninfected length is at least 512 bytes.

       Systems infected with the 512 virus may experience program crashes
       due to unexpected errors, as well as system hangs.  Damage may occur
       to infected files if the system user runs CHKDSK with the /F
       parameter as the length of the program in the directory entry will not
       match the actual disk space used.  CHKDSK will then adjust the file
       allocation resulting in damaged files.

       The virus's alias of "Number of the Beast" Virus is because the
       author of the virus used a signature of text 666 near the end of the
       virus to determine if the file is already infected.  Since 512 adds
       its viral code to the end of infected files, it is easy to verify
       that a file is infected by the 512 virus by checking for this
       signature.

       Known variant(s) of the 512 Virus are:
       512-B : Similar to the 512 Variant, except that the DOS version check
               in the original virus has been omitted.  The author's
               signature of '666' has been omitted.
       512-C : Similar to the 512-B Variant, minor code changes.
       512-D : Similar to the 512-C Variant, except that the virus no longer
               checks to see if a file has the System Attribute on it before
               infecting it.
       512-E : Similar to the other 512 viruses, this variant will use some
               memory about 640K, such as memory on video cards.  Infected
               systems will have a 55,104 byte decrease in total system and
               available free memory as indicated by the DOS ChkDsk program.
               This variant does not use the text 666 signature to designate
               infected files.
       512-F : Similar to other variants, the DOS ChkDsk program will not show
               any decrease in system or available memory when the virus is
               resident.  The "666" text signature can be found in infected
               files as offset 1FD.


 Virus Name:  646
 Aliases:     Vienna C, Vienna 646
 V Status:    Rare
 Discovery:   October, 1990
 Symptoms:    COMMAND.COM & .COM growth
 Origin:      Unknown
 Eff Length:  646 Bytes
 Type Code:   PNCK - Parasitic Non-Resident COM Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Pro-Scan 2.01+, Scan/D, or Delete infected files
 General Comments:
       The 646 Virus was discovered in October, 1990.  Its origin is unknown.
       This virus is a non-resident infector of .COM files, including
       COMMAND.COM.

       When a file infected with the 646 Virus is executed, the virus will
       infect one other .COM file in the current directory.  Infected files
       will increase in size by 646 bytes, with the virus being located at
       the end of the infected file.

       Infected files can be easily identified as they will always end with
       the hex string: "EAF0FFFFFF".

       This virus appears to do nothing except replicate.


 Virus Name:  834 Virus
 Aliases:     Arab
 V Status:    Rare
 Discovery:   February, 1991
 Symptoms:    .COM file growth; TSR; Partition Table altered;
              Unexpected disk accesses to hard disk;
              Attempts to boot system from hard disk may hang
 Origin:      Unknown
 Eff Length:  834 Bytes
 Type Code:   PRsC - Parasitic Resident COM Infector
 Detection Method: ViruScan V76+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The 834 Virus was received in February, 1991.  Its origin is unknown.
       This virus is a memory resident infector of .COM files, but not
       COMMAND.COM.

       The first time a program infected with the 834 Virus is executed, the
       virus will install itself memory resident as a low system memory TSR
       of 1,808 bytes.  Interrupt 21 will be hooked by the virus as well.  At
       this time, the virus will access the hard disk partition table, altering
       it.

       After the 834 Virus is memory resident, it will infect .COM files of
       a length greater than 4K in length as they are executed.  COMMAND.COM,
       however, will not be infected.  Infected files will increase in length
       by 834 bytes, the virus will be located at the end of the infected
       program.  The file date and time in the disk directory is not altered
       by the virus.

       Systems infected with the 834 Virus may notice unexpected accesses to
       the system hard disk when executing programs from a diskette.  These
       accesses are the virus accessing the hard disk partition table each
       time an infected program is executed, or a program is infected by the
       virus.  The system's hard disk partition table does not contain an
       infectious copy of the virus, but has been altered so that later
       attempts to boot the system from the system hard disk may result in a
       system hang occurring during the boot process.

       Known variant(s) of 834 include:
       834-B/Arab: Similar to the original virus, this variant will infect
                .COM files other than COMMAND.COM which are greater than 1K in
                length before infection.  Two text strings occur within this
                variant's code: "nsed Materi" and "COMMAND.COM".  Low system
                memory TSR is 1,792 bytes in length.


 Virus Name:  903
 Aliases:     FichV
 V Status:    Rare
 Discovery:   January, 1991
 Symptoms:    .COM file growth; TSR; System hangs
 Origin:      France
 Eff Length:  903 Bytes
 Type Code:   PRsCK - Parasitic Resident COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The 903 Virus was discovered France in January, 1991.  This virus is
       not a particularly viable virus since replicated samples will not
       further replicate.  It is possible that the original sample is
       corrupted.  This virus infects .COM program, including COMMAND.COM.

       When the original sample of 903 is executed, this virus will install
       itself memory resident as a 1,216 byte low system memory TSR.  It will
       hook interrupt 21.  At that time, it will infect COMMAND.COM, adding
       903 bytes to the beginning of the program.  The following message is
       then displayed:

               "Fichier introuvable"

       Once memory resident, this virus will infect up to three .COM programs
       in the current directory if the original sample is again executed.
       Later execution of infected files (other than the original) will not
       result in the virus spreading to other files.  The virus will also
       infect files when the DOS Copy command is used, but only if the source
       and target files are in the current directory.

       Infected .COM programs will have a file size increase of 903 bytes,
       the virus will be located at the beginning of the infected program.
       The file date and time in the disk directory will not be altered by
       the virus.

       If 903 becomes memory resident from other than the original sample, it
       will not replicate to other .COM programs.  The "Fichier introuvable"
       message is not displayed with other than the original sample.

       Some programs may hang when they are executed on infected systems.

       It is unknown if 903 does anything destructive.

       Known variant(s) of 903 include:
       903-B  : Similar to the original 903 Virus, will infect three files
                each time an infected program is executed, including when the
                virus becomes memory resident.  The message from the original
                virus is never displayed.  It has six bytes which are different
                from the original virus.


 Virus Name:  1008
 Aliases:     Suomi, Oulu
 V Status:    Rare
 Discovery:   June, 1990
 Symptoms:    COMMAND.COM growth, Internal Stack Errors,
              System Halt on Boot
 Origin:      Helsinki, Finland
 Eff Length:  1,008 Bytes
 Type Code:   PRCK - Parasitic Resident COM Infector
 Detection Method:  ViruScan V64+, F-Prot 1.12+, Pro-Scan 2.01+, NAV,
              IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, Pro-Scan 2.01+, NAV,
              or delete infected files
 General Comments:
       The 1008 Virus was discovered in June, 1990 by Petteri Jarvinen of
       Helsinki, Finland.  It is a memory resident .COM infector, and will
       infect COMMAND.COM.  This virus is also sometimes referred to as
       the Suomi Virus.

       The first time a program infected with the 1008 virus is executed,
       the virus will install itself memory resident.  COMMAND.COM is also
       infected at this time, resulting in its length increasing by 1,008
       Bytes.  The increase in file size of COMMAND.COM cannot be seen by
       doing a directory listing if the virus is present in memory.

       Booting a system with an infected copy of COMMAND.COM may result in
       an internal stack error, and the system being halted.  This effect
       was noted on the author's test machine which is a 640K XT-clone
       running Microsoft MS-DOS Version 3.30.

       After the virus is memory resident, it will infect any .COM file which
       is executed, adding 1,008 bytes to the file length.  The file length
       increase cannot be seen by doing a directory listing if the virus is
       present in memory.


 Virus Name:  1210
 Aliases:     Prudents Virus
 V Status:    Rare
 Discovery:   December, 1989
 Symptoms:    .EXE growth, disk write failure, TSR
 Origin:      Spain
 Eff Length:  1,210 Bytes
 Type Code:   PRE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan V61+, Pro-Scan 1.4+, F-Prot 1.12+, VirHunt 2.0+,
              NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, VirHunt 2.0+, NAV,
              or delete infected files
 General Comments:
       The 1210, or Prudents Virus, was first isolated in Barcelona, Spain,
       in December 1989.  The 1210 is a memory resident virus, infecting
       .EXE files when they are executed.

       This virus activates between May 1st and May 4th of any year,
       causing disk writes to be changed to disk verifies, so writes to
       the disk never occur between these dates.


 Virus Name:  1226
 Aliases:     V1226
 V Status:    Rare
 Discovery:   July 1990
 Symptoms:    .COM growth, decrease in system and free memory, system hangs,
              spurious characters displayed in place of program executing,
              disk drive spinning
 Origin:      Bulgaria
 Eff Length:  1,226 Bytes
 Type Code:   PRhC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The 1226 Virus was isolated in Bulgaria in July 1990 by Vesselin
       Bontchev.  This virus is a memory resident generic .COM infector,
       though it does not infect COMMAND.COM.  The 1226 Virus is a self-
       encrypting virus, and simple search string algorithms will not work
       to detect its presence on a system.

       The first time a program infected with the 1226 virus is executed,
       the virus will install itself memory resident, reserving 8,192 bytes
       of memory at the top of free memory.  Interrupt 2A will be hooked.

       Once 1226 is memory resident, the virus will attempt to infect any
       .COM file that is executed that is at least 1,226 bytes in length
       before infection.  The virus is rather "buggy" and the infection
       process is not always entirely successful.  Successfully infected
       files will increase in length by 1,226 bytes.

       This virus will infect .COM files multiple times, it is unable to
       determine that the file is already infected.  Each time the file
       is infected it will grow in length by another 1,226 bytes.  Eventually,
       the .COM files will grow too large to fit into memory.

       Systems infected with the 1226 virus may experience unexpected system
       hangs when attempting to execute programs.  Another affect is that
       instead of a program executing, a line or two of spurious characters
       will appear on the system display.  Lastly, infected systems will always
       indicate that they have 8,192 less bytes of total system and free
       memory available than is actually on the machine.

       There are two later versions of this virus, 1226D and 1226M, which are
       much better replicators than the original 1226 virus.  These two
       variants are documented as 1226D in this document due to their
       different characteristics.

       Also see: 1226D


 Virus Name:  1226D
 Aliases:     V1226D
 V Status:    Rare
 Discovery:   July 1990
 Symptoms:    .COM growth, decrease in system and free memory
 Origin:      Bulgaria
 Eff Length:  1,226 Bytes
 Type Code:   PRhC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+, NAV
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The 1226D Virus was isolated in Bulgaria in July 1990 by Vesselin
       Bontchev.  This virus is a memory resident generic .COM infector,
       though it does not infect COMMAND.COM.  The 1226D Virus is a self-
       encrypting virus, and simple search string algorithms will not work
       to detect its presence on a system.

       The 1226D Virus is based on the 1226 Virus, in fact it is a decrypted
       version of the 1226 Virus.  It is a better replicator, infecting
       successfully on file opens as well as when .COM files are executed.

       The first time a program infected with the 1226 virus is executed,
       the virus will install itself memory resident, reserving 8,192 bytes
       of memory at the top of free memory.  Total system and free memory
       are decreased by 8,192 bytes.  Interrupt 2A will be hooked.

       Once 1226 is memory resident, the virus will attempt to infect any
       .COM file that is executed that is at least 1,226 bytes in length
       before infection.  Infected files will increase in length by 1,226
       bytes.  As with the original 1226 Virus, a .COM file may be infected
       multiple times by the 1226D Virus as the virus is unable to determine
       that the file was previously infected.  Each infection will result in
       another 1,226 bytes being added to the infected file's length.
       Eventually, the .COM files will grow too large to fit into memory.

       In addition to infecting .COM files when they are executed, the 1226D
       Virus will infect .COM files with a length of at least 1,226 bytes
       when they are openned for any reason.  The simple act of copying a
       .COM file with the virus memory resident will result in both the
       source and target files being infected.

       Unlike the 1226 Virus, systems infected with the 1226D virus will not
       experience the system hangs or spurious characters symptomatic of the
       1226 virus.  Infected system will still indicate that they have 8,192
       bytes less of total system memory than is installed on the machine.

       Known variant(s) of 1226D are:
       1226M/V1226M : Similar to the 1226D virus, except that files are not
                 infected on file open, only when they are executed.

       Also see: 1226


 Virus Name:  1253
 Aliases:     AntiCad, V-1
 V Status:    Rare
 Discovery:   August, 1990
 Symptoms:    TSR; BSC; COMMAND.COM & .COM file growth; partition table change
 Origin:      Austria
 Eff Length:  1,253 Bytes
 Type Code:   PRsBCKX - Parasitic Resident .COM & Partition Table Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: Pro-Scan 2.01+, NAV, Scan/D plus MDisk/P
 General Comments:
       The 1253 Virus was submitted in August 1990.  It is believed to have
       originated in (or at least to have been first isolated in) Austria.
       1253 is a generic infector of .COM files, including COMMAND.COM.
       It also infects the boot sector of diskettes and the partition table
       of hard disks.

       The first time a program infected with the 1253 Virus is executed, the
       virus will install itself memory resident as a low system memory TSR.
       The TSR will be 2,128 bytes in length, hooking interrupts 08, 13, 21,
       and 60.  Total system memory will remain unchanged, and free memory
       will decrease by 2,128 bytes.  At this time, the partition table of
       the system's hard disk is infected with the 1253 virus.  If the
       infected program was executed from a diskette, the diskette's boot
       sector will also be infected.

       Each time a .COM file is executed with the virus resident in memory,
       the .COM file will be infected if it hasn't previously been infected.
       The 1253 Virus appends its viral code to the end of the .COM file, and
       then changes the first few bytes of the program to be a jump to the
       appended code.  Infected files increase in length by 1,253 bytes, and
       the virus makes no attempt to hide the increase when the directory
       is displayed.  Infected files will also have their fourth thru sixth
       bytes set to "V-1" (hex 562D31).

       Any diskettes which are accessed while the virus is present in memory
       will have their boot sector infected with this virus.  Newly formatted
       diskettes, likewise, will be infected immediately.

       The 1253 virus is destructive when it activates.  The author of this
       listing was able to get it to activate by setting the system date to
       December 24 and then executing an infected program on drive A:.  The
       virus promptly went and overwrote the entire diskette in drive
       A: with a pattern of 9 sectors of what appears to be a program
       fragment.  Once the virus has started to overwrite a diskette, the
       only way to stop the disk activity is to power off the system.

       The virus in the partition table and/or diskette boot sector is of
       special note.  When the system is booted from the hard disk or diskette
       with the virus in the partition table or boot sector, the virus will
       install itself memory resident.  At this time, the virus resides above
       the top of system memory but below the 640K DOS boundary.  The change
       in total system memory and available free memory will be 77,840 bytes.
       It can be seen with the CHKDSK command.  At this time, any .COM program
       executed will be infected with the 1253 virus, even though no programs
       on the hard disk may contain this virus before the system boot occurred.

       One effect of this virus, once the system has been booted from an
       infected hard drive or floppy is that the FORMAT command may result
       in unexpected disk activity to inactive drives.  For example, on the
       author's system, when formatting a diskette in drive A: with the
       current drive being drive C:, there was always disk activity to drive
       B:.

       Disinfecting the 1253 virus required that besides disinfecting or
       deleting infected .COM programs, the hard disks partition table and the
       boot sector of any diskettes exposed to the infected system must be
       disinfected.  The virus can be removed safely from the partition table
       and diskette boot sectors by using MDisk with the /P option after
       powering off the system and rebooting from a write-protected uninfected
       boot diskette.  If the partition table and diskette boot sectors are
       not disinfected, the system will promptly experience reinfection of
       .COM files with the virus following a system boot from the hard disk
       or diskette.  Disinfecting the partition table and boot sectors, when
       done properly, will also result in the system's full memory again being
       available.

       It is unknown if there are other activation dates for this virus, or
       if it will overwrite the hard disk if an infected program is executed
       on December 24 from the hard disk.


 Virus Name:  1260
 Aliases:     V2P1
 V Status:    Research
 Discovery:   January, 1990
 Symptoms:    .COM file growth
 Origin:      Minnesota, USA
 Eff Length:  1,260 Bytes
 Type Code:   PNC - Parasitic Encrypting Non-Resident .COM Infector
 Detection Method:  ViruScan V57+, IBM Scan, Pro-Scan 1.4+, F-Prot 1.12+,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: CleanUp V57+, Pro-Scan 1.4+, F-Prot 1.12+, VirHunt 2.0+
 General Comments:
       The 1260 virus was first isolated in January, 1990.  This
       virus does not install itself resident in memory, but is it
       extremely virulent at infecting .COM files.  Infected files
       will have their length increased by 1,260 bytes, and the
       resulting file will be encrypted.  The encryption key changes
       with each infection which occurs.

       The 1260 virus is derived from the original Vienna Virus, though
       it is highly modified.

       This virus was developed as a research virus by Mark Washburn, who
       wished to show the anti-viral community why identification string
       scanners do not work in all cases.  The encryption used in 1260 is
       one of many possible cases of the encryption which may occur with
       Washburn's later research virus, V2P2.

       Also see: V2P2, V2P6, V2P6Z


 Virus Name:  1381 Virus
 Aliases:     Internal
 V Status:    Rare
 Discovery:   June, 1990
 Symptoms:    .EXE growth
 Origin:
 Eff Length:  1,381 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method:  ViruScan V64+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The 1381 Virus was isolated in June, 1990.  It is a non-resident
       generic .EXE infector.

       Each time a program infected with the 1381 Virus is executed, the
       virus will attempt to infect one other .EXE file on the current
       drive.  An .EXE file will only be infected if it is greater than
       1,300 bytes in length before infection.  After infection, files
       will have increased in length by between 1,381 and 1,389 bytes.

       The virus can be found at the end of infected files.  Infected
       files will also contain the following text strings:

              "INTERNAL ERROR 02CH.
               PLEASE CONTACT YOUR HARDWARE MANUFACTURER IMMEDIATELY !
               DO NOT FORGET TO REPORT THE ERROR CODE !"

       It is currently unknown what the 1381 Virus does, or what prompts
       it to display the above message.

       Known variant(s) of 1381 include:
       1381-B/Internal: Similar to the original 1381 virus, this variant is
                very similar. The major change is that it does not always
                infect a .EXE file each time an infected program is executed.
                The increase in file length on infected files will 1,381 to
                1,395 bytes, and the virus will be located at the end of the
                infected file.  The message text indicated above for the
                original virus will be displayed if the year is 1991 or greater.
                When the message is displayed, the program that was being
                executed will be disinfected by the virus.


 Virus Name:  1392
 Aliases:     Amoeba Virus
 V Status:    Rare
 Discovery:   March, 1990
 Symptoms:    TSR, .COM & .EXE growth, dates modified
 Origin:      Indonesia
 Eff Length:  1,392 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method: ViruScan V61+, VirexPC 1.1+, F-Prot 1.12+, VirHunt 2.0+,
              NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, VirHunt 2.0+, NAV,
              or delete infected files
 General Comments:
       The 1392, or Amoeba, Virus was first isolated in Indonesia in
       March 1990.  The 1392 virus is a memory resident virus that infects
       .COM and .EXE files, including COMMAND.COM.  As files are infected,
       their creation/modification date is changed to the date the files
       were infected.

       This virus does not appear to cause any destructive damage.

       The following message appears in the virus, which is where its
       alias of Amoeba was derived from:

              "SMA KHETAPUNK - Nouvel Band A.M.O.E.B.A"


 Virus Name:  1554
 Aliases:     Ten Bytes, 9800:0000 Virus, V-Alert, 1559
 V Status:    Rare
 Discovery:   February, 1990
 Symptoms:    .COM & .EXE growth, TSR, linkage corruption, system hang
 Origin:
 Eff Length:  1,554 Bytes
 Type Code:   PRfAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V58+, IBM Scan, Pro-Scan 1.4+, VirexPC 1.1+,
              AVTK 3.5+, F-Prot 1.12+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D, F-Prot 1.12+, VirHunt 2.0+, Pro-Scan 2.01+
 General Comments:
       The 1554 virus was accidently sent out over the VALERT-L network
       on February 13, 1990 to approximately 600 subscribers.  When a
       program is executed that is infected with the 1554 virus, the
       virus installs itself memory resident.  It will then proceed to
       infect .COM over 1000 bytes in length and .EXE files over 1024 bytes
       in length, including COMMAND.COM, increasing their length after
       infection by 1,554 to 1,569 bytes.

       The 1554 virus activates in September, October, November, or
       December of any year.  Upon activation, any files which are written
       will be missing the first ten bytes.  At the end of these files,
       ten bytes of miscellaneous characters will appear.  In effect, both
       programs and data files will be corrupted.

       If the 1554 Virus is executed on a system with less than 640K of
       system memory, the virus will hang the system.


 Virus Name:  1575
 Aliases:     1577, 1591
 V Status:    Common
 Discovery:   January, 1991
 Symptoms:    .COM & .EXE growth; decrease in total system & available memory;
              Sluggishness of DIR commands; file date/time changes
 Origin:      Taiwan
 Isolated:    Ontario, Canada
 Eff Length:  1,575 Bytes
 Type Code:   PRfAk - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+, IBM Scan 2.00+
 Removal Instructions: Scan/D, Clean-Up V74+, or Delete infected files
 General Comments:
       The 1575 virus was first isolated in Ontario, Canada, in January, 1991.
       This virus has been widely reported, and is believed to be from the Far
       East, probably Taiwan.  It is a memory resident infector of .COM and
       .EXE files, and will infect COMMAND.COM.

       When the first program infected with the 1575 Virus is executed, the
       virus will install itself memory resident in 1,760 to 1,840 bytes at
       the top of system memory, but below the 640K DOS boundary.  This
       memory is not reserved, and may be overwritten later by another
       program.  Interrupt 21 will be hooked by the virus.  COMMAND.COM on
       the system C: drive root directory will also be infected at this
       time.

       Once the 1575 Virus is memory resident, it will infect one .COM and
       one .EXE program on the current drive whenever a DOS Dir or Copy
       command is executed.  This virus does not spread when programs are
       executed.

       Infected files will have their file date and time in the DOS directory
       updated to the system date and time when the infection occurred.
       Their file lengths will also show an increase of between 1,577 and
       1,591 bytes.  This virus will be located at the end of infected files.

       It is not know if 1575 does anything besides replicate.

       Known variant(s) of the 1575 Virus are:
       1575-B : This variant is functionally similar to the 1575 Virus
                described above.  The major difference is that this variant
                reserves the memory it occupies at the top of system memory,
                though the interrupt 12 return is not moved.
       1575-C : Similar to the 1575-B, this variant will infect files as they
                are executed in addition to when a DOS Dir or Copy command
                is issued.  System may hang when this variant infects
                COMMAND.COM.


 Virus Name:  1605
 Aliases:     1605-B, Solomon, Tel Aviv
 V Status:    Rare
 Discovery:   September, 1990
 Symptoms:    .COM & .EXE growth; TSR; system slowdown
 Origin:      Unknown
 Eff Length:  1,605 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: NAV, Scan/D, or Delete infected files
 General Comments:
       The 1605 Virus was uploaded to John McAfee's Homebase BBS by an
       anonymous user in September, 1990.  The origin of this virus is
       unknown.  The 1605 Virus is a memory resident infector of .COM
       and .EXE files, and it does not infect COMMAND.COM.  It is based
       roughly on the Jerusalem B Virus.

       The first time a program infected with the 1605 Virus is executed,
       the virus will install itself memory resident as a low system memory
       TSR of 1,728 bytes.  Interrupts 13 and 21 will be hooked by the
       virus.  At this time, the system will slowdown by approximately
       15-20%.

       After becoming memory resident, any .COM or .EXE file executed will
       be infected by the virus.  .COM files will increase in size by
       1,605 bytes in all cases with the virus's code being located at the
       beginning of the file.  .EXE files will increase in size by between
       1,601 and 1,610 bytes with the virus's code being located at the
       end of the infected file.

       Other than replicating, it is unknown if this virus carries any
       damage potential.

       Known variant(s) of the 1605 Virus are:
       1605-B  : This variant was received by MicroCom in London, England in
                 March 1991 in a plain envelope with a London postmark.  The
                 label on the diskette read "Solomon Virus", though the virus
                 is not related in any way to Dr. Solomon.  This variant is
                 very similar to the 1605 virus described above, the major
                 difference is that infected .EXE files will increase in size
                 by 1,605 to 1,619 bytes.


 Virus Name:  1704 Format
 Aliases:
 V Status:    Rare
 Discovery:   January, 1989
 Symptoms:    TSR, Falling letters, .COM growth, formatted disk
 Origin:
 Eff Length:  1,704 Bytes
 Type Code:   PRC - Parasitic Encrypting Resident .COM Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVKT 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: CleanUp, Scan/D, F-Prot, Pro-Scan, VirexPC, VirHunt 2.0+
 General Comments:
       Like the Cascade Virus, but the disk is formatted when the
       virus activates.  Activation occurs during the months of
       October, November, and December of any year except 1993.


 Virus Name:  1720
 Aliases:     PSQR Virus
 V Status:    Rare
 Discovery:   March, 1990
 Symptoms :   TSR, .COM & .EXE growth, partition table damage on activation,
              programs on diskette deleted on Friday The 13ths
 Origin:      Spain
 Eff Length:  1,720 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method: ViruScan V61+, VirexPC 1.1+, F-Prot 1.12+, VirHunt 2.0+,
              Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: NAV, Scan /D, VirHunt 2.0+, or delete infected files
 General Comments:
       The 1720, or PSQR Virus, is a variant of the Jerusalem Virus which
       was first isolated in Barcelona, Spain, in March 1990.  This virus,
       infects .COM and .EXE files, though unlike Jerusalem, it does not
       infect Overlay files.  COMMAND.COM will also not be infected.

       The first time an infected file is executed, the virus will install
       itself memory resident, and then infect each executable file as it
       is run.

       On Friday The 13ths, the 1720 Virus will activate the first time an
       infected program is executed.  When the program is executed, it will
       be deleted from disk.  More damaging, however, is that the 1720 virus
       will check to see if the system has a hard disk drive.  If a hard
       disk drive is present, the virus will overwrite the boot sector and
       partition table resulting in all data on the hard disk becoming
       unavailable.  The system will also appear to hang.


 Virus Name:  2560
 Aliases:
 V Status:    New
 Discovery:   April, 1991
 Symptoms:    .COM & .EXE growth; Decrease in system & available memory
 Origin:      Unknown
 Eff Length:  2,560 Bytes
 Type Code:   PRhA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V77+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The 2560 Virus was received in April, 1991.  Its origin or discovery
       location is unknown.  This virus is a memory resident infector of .COM
       and .EXE files, it does not infect COMMAND.COM.

       The first time a program infected with the 2560 Virus is executed,
       2560 will install itself memory resident at the top of system memory
       but below the 640K DOS boundary.  Interrupt 12's return is not moved.
       Interrupts 08, 13, 21, and 22 will be hooked by the virus.  Total
       system and available free memory, as measured by the DOS ChkDsk program,
       will decrease by 5,184 bytes.

       After becoming memory resident, 2560 will infect .COM and .EXE programs
       over approximately 3K in length when they are executed or openned for
       any reason.  Infected programs will have a file length increase of
       2,560 bytes with the virus being located at the end of the file.  The
       date and time in the DOS disk directory will not be altered.

       The DOS Edlin program will fail to function properly once infected
       with 2560.  Attempts to execute Edlin will result in the message
       "Invalid drive or file name" being displayed, and then Edlin will
       terminate leaving the user at a DOS prompt.

       It is unknown what 2560 does besides replicate.


 Virus Name:  4096
 Aliases:     Century Virus, FroDo, IDF Virus, Stealth Virus, 100 Years Virus
 V Status:    Common
 Discovery:   January, 1990
 Symptoms:    .COM, .EXE, & overlay file growth; TSR hides growth; crosslinks;
              corruption of data files
 Origin:      Israel
 Eff Length:  4,096 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V53+, F-Prot, IBM Scan, Pro-Scan, VirexPC 1.1+,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: CleanUp V62+, Pro-Scan 1.4+, F-Prot, VirHunt 2.0+,
              NAV, or see note below
 General Comments:
       The 4096 virus was first isolated in January, 1990.  This virus
       is considered a Stealth virus in that it is almost invisible
       to the system user.

       The 4096 virus infects .COM, .EXE, and Overlay files, adding
       4,096 bytes to their length.  Once the virus is resident in
       system memory, the increase in length will not appear in a
       directory listing.  Once this virus has installed itself into
       memory, it will infect any executable file that is opened,
       including if it is opened with the COPY or XCOPY command.

       This virus is destructive to both data files and executable
       files, as it very slowly crosslinks files on the system's
       disk.  The crosslinking occurs so slowly that it appears there
       is a hardware problem, the virus being almost invisible.  The
       crosslinking of files is the result of the virus manipulating
       the FATs, changing the number of available sectors, as well as
       the user issuing CHKDSK/F commands which will think that the
       files have lost sectors or crosslinking if the virus is in
       memory.

       As a side note, if the virus is present in memory and you
       attempt to copy infected files, the new copy of the file will
       not be infected with the virus if the new copy does not have
       an executable file extension.  Thus, one way to disinfect
       a system is to copy off all the infected files to diskettes with a
       non-executable file extension (ie. don't use .EXE, .COM, .SYS, etc)
       while the virus is active in memory, then power off the system
       and reboot from a write protected (uninfected) system disk.
       Once rebooted and the virus is not in memory, delete the
       infected files and copy back the files from the diskettes to the
       original executable file names and extensions.

       The above will disinfect the system, if done correctly, but
       will still leave the problem of cross-linked files which are
       permanently damaged.

       On or after September 22 of any year, the 4096 virus will hang
       infected systems.  This appears to be a "bug" in the virus in that
       it goes into a time consuming loop.

       The 4096 virus also contains a boot-sector within its code, however,
       it is never written out to the disk's boot sector.  Moving this
       boot sector to the boot sector of a diskette and rebooting the
       system will result in the message "FRODO LIVES" being displayed.
       September 22 is Bilbo and Frodo Baggin's birthday in the Lord Of
       The Rings trilogy.

       An important note on the 4096 virus: this virus will also infect some
       data files.  When this occurs, the data files will appear to be fine
       on infected systems.  However, after the system is later disinfected,
       these files will now be corrupted and unpredictable results may occur.

       Known variant(s) of the 4096 virus include:
       4096-B    : Similar to the 4096 virus, the main change is that the
                   encryption mechanism has been changed in order to avoid
                   detection.
       4096-C    : Isolated in January, 1991, this variant of 4096 is similar
                   to the original virus.  The major difference is that the
                   DOS ChkDsk command will not show any cross-linking of files
                   or lost clusters.  A symptom of infection by this variant
                   is that the disk space available according to a DIR command
                   will be more than the disk space available according to the
                   DOS ChkDsk program.


 Virus Name:  4870 Overwriting
 Aliases:
 V Status:    Rare
 Discovery:   February, 1991
 Origin:      Unknown
 Symptoms:    Programs fail to execute; Program corruption
 Eff Length:  4,870 Bytes
 Type Code:   ONAK - Overwriting Non-Resident .COM & .EXE Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The 4870 Overwriting Virus was isolated in February, 1991.  It's origin
       or isolation point is not known.  This virus is a non-resident direct
       action virus that infects .COM and .EXE programs, including
       COMMAND.COM.

       When a program infected with the 4870 Overwriting Virus is executed,
       the virus will search the current directory for an uninfected .COM or
       .EXE file.  The first such uninfected file located will be infected
       by the virus.  Infected programs will have the first 4,870 bytes of
       the candidate program overwritten by the virus.  If the program's
       original length was 4,870 bytes or more, there will be no increase in
       the file length in the DOS directory.  If the program's original
       length was less than 4,870 bytes, then the program's length in the DOS
       directory will now be 4,870 bytes.  The file's date and time in the
       directory will not be altered.

       Programs infected with the 4870 Overwriting Virus will not execute
       properly.  Once the virus checked for a program to infect, and infected
       the candidate program if one was found, the virus will terminate and
       return the user to a DOS prompt.

       A side note on this virus: the virus itself is compressed with the
       LZEXE utility, which accounts for much of the 4,870 bytes of viral code.
       Programs infected with this virus will have the markers of LZEXE version
       .91 found in the first 4,870 bytes of the infected program.

       It is not possible to disinfect programs infected with the 4870
       Overwriting Virus as the first 4,870 bytes of the original program
       are lost.  Infected programs must be deleted or erased, then replaced
       with clean copies.


 Virus Name:  5120
 Aliases:     VBasic Virus, Basic Virus
 V Status:    Rare
 Discovery:   May, 1990
 Origin:      West Germany
 Symptoms:    .COM & .EXE growth, file corruption, unexpected disk activity
 Eff Length:  5,120 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan 1.4+, F-Prot 1.12+,
              IBM Scan 2.00+
 Removal Instructions: Scan/D/X, Pro-Scan 1.4+, F-Prot 1.12+, Pro-Scan 2.01+,
              or Delete infected files
 General Comments:
       The 5120 Virus was first isolated in May, 1990.  It is a non-
       resident generic file infector, infecting .COM and .EXE files,
       including COMMAND.COM.  This virus is was written in compiled Turbo
       Basic with some assembly language.

       When an infected file is executed, the 5120 virus will infect one
       .COM and one .EXE file on the current drive and directory, followed
       by attempting to infect one randomly selected .COM or .EXE file in
       each directory on the system's C: drive.  Infected .COM files increase
       in length by 5,120 bytes.  .EXE files infected by the 5120 Virus will
       increase in length by between 5,120 and 5,135 bytes.

       Unlike most of the MS-DOS viruses, the 5120 Virus does not intercept
       disk write errors when attempting to infect programs.  Thus, infected
       systems may notice disk write error messages when no access should be
       occurring for a drive, such as the C: hard disk partition.

       Data files may become corrupted on infected systems, as well as
       crosslinking of files may occur.

       The following text strings can be found in files infected with the
       5120 virus.  These strings will appear near the end of the file:

               "BASRUN"
               "BRUN"
               "IBMBIO.COM"
               "IBMDOS.COM"
               "COMMAND.COM"
               "Access denied"

       There is one variant of the 5120 Virus which does not contain the
       above strings, but behaves in a very similar manner.  This second
       variant is not indicated here as the author does not have a copy.


 Virus Name:  AIDS
 Aliases:     Hahaha, Taunt, VGA2CGA
 V Status:    Endangered
 Discovery:   1989
 Symptoms:    Message, .COM file corruption
 Origin:
 Eff Length:  N/A
 Type Code:   ONC - Overwriting Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan, VirexPC 1.1+, AVTK 3.5+
 Removal Instructions:  Scan/D/X, or delete infected .COM files
 General Comments:
       The AIDS virus, also known as the Hahaha virus in Europe and
       referred to as the Taunt virus by IBM, is a generic .COM and
       .EXE file infector.  When the virus activates, it displays the
       message "Your computer now has AIDS", with AIDS covering
       about half of the screen.  The system is then halted, and
       must be powered down and rebooted to restart it.  Since this
       virus overwrites the first 13,952 bytes of the executable program, the
       files must be deleted and replaced with clean copies in order
       to remove the virus.  It is not possible to recover the
       overwritten portion of the program.

       Note: this is NOT the Aids Info Disk/PC Cyborg Trojan.

       Known variant(s) of Aids are:
       Aids B : Very similar to the original Aids Virus, this variant is also
                13,952 bytes in length.  Unlike the original virus, it will
                only infect .COM files, as well as COMMAND.COM, and does not
                activate as the original virus did.  Instead, this variant
                will occasionally issue the following error message:
                "I/O error 99, PC=2EFD
                 Program aborted".
                This variant was received in January, 1991, origin unknown.


 Virus Name:  Aids II Virus
 Aliases:     Companion Virus
 V Status:    Endangered
 Discovery:   April, 1990
 Symptoms:    Creates .COM files, melody, message
 Origin:
 Eff Length:  8,064 Bytes
 Type Code:   SNA - Spawning Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan 1.4+, NAV
 Removal Instructions: Scan/D/X, or delete corresponding .COM files
 General Comments:
       The Aids II Virus, or Companion Virus, was isolated for the first
       time in April 1990.  Unlike other generic file infectors, the
       Aids II Virus is the first known virus to employ what could be
       termed a "corresponding file technique" of infection so that the
       original target .EXE file is never changed.  The virus takes
       advantage of the DOS feature where if a program exists in both
       .COM and .EXE form, the .COM file will be executed.

       The Aids II Virus does not directly infect .EXE files, instead it
       stores a copy of the virus in a corresponding .COM file which will
       be executed when the user tries to execute one of his .COM files.
       The .EXE file, and the .COM file containing the viral code will
       both have the same base file name.

       The method of infection is as follows:  when an "infected"
       program is executed, since a corresponding .COM file exists, the
       .COM file containing the viral code is executed.  The virus
       first locates an uninfected .EXE file in the current directory and
       creates a corresponding (or companion) .COM file with the viral
       code.  These .COM files will always be 8,064 Bytes in length with
       a file date/time of the date/time of infection.  The .EXE file is
       not altered at all.  After creating the new .COM file, the virus
       then plays a melody and displays the following message, the "*"
       indicated below actually being ansi heart characters:

                 "Your computer is infected with ...

                           * Aids Virus II *

                  - Signed WOP & PGT of DutchCrack -"

       The Aids II Virus then spawns to the .EXE file that was attempting
       to be executed, and the program runs without problem.  After
       completion of the program, control returns to the Aids II Virus.
       The melody is played again with the following message displayed:

                        "Getting used to me?

                    Next time, use a Condom ....."

       Since the original .EXE file remains unaltered, CRC checking
       programs cannot detect this virus having infected a system.

       One way to manually remove the Aids II Virus is to check the
       disk for programs which have both a .EXE and a .COM file, with
       the .COM file having a length of 8,064 bytes.  The .COM files
       thus identified should be erased.

       The displayed text strings do not appear in the viral code.


 Virus Name:  AirCop
 Aliases:
 V Status:    Rare
 Discovery:   July, 1990
 Isolated:    Washington, USA
 Symptoms:    BSC; System Halt; Message; decrease in system and free memory
 Origin:      Taiwan
 Eff Length:  N/A
 Type Code:   FR - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions:  CleanUp V77+, MDisk or DOS SYS command
 General Comments:
       The AirCop Virus was discovered in the State of Washington in the
       United States in July, 1990.  Some early infections of this virus,
       however, have been traced back to Taiwan, and Taiwan is probably where
       it originated.  AirCop is a boot sector infector, and it will only
       infect 360K 5.25" floppy diskettes.

       When a system is booted from a diskette which is infected with the
       AirCop virus, the virus will install itself memory resident.  The
       AirCop Virus installs itself memory resident at the top of high system
       memory.  The system memory size and available free memory will
       decrease by 1,024 bytes when the AirCop virus is memory resident.
       AirCop hooks interrupt 13.

       Once AirCop is memory resident, any non-write protected diskettes
       which are then accessed will have their boot sector infected with
       the AirCop virus.  AirCop will copy the original disk boot sector
       to sector 719 (Side 1, Cyl 39, Sector 9 on a normal 360K 5.25"
       diskette) and then replace the boot sector at sector 0 with a copy
       of the virus.  If a boot sector of a diskette infected with the
       AirCop virus is viewed, it will be missing almost all of the messages
       which normally appear in a normal boot sector.  The only message
       remaining will be:

               "Non-system..."

       This will be located just before the end of the boot sector.

       The AirCop Virus will do one of two things on infected systems,
       depending on how compatible the system's software and hardware is
       with the virus.  On most systems, the virus will display the following
       message at random intervals:

               "Red State, Germ Offensive.
                AIRCOP."

       On other systems, the virus being present will result in the system
       receiving a Stack Overflow Error and the system being halted.  In this
       case, you must power off the system in order to be able to reboot.

       AirCop currently does not infect hard disk boot sectors or partition
       tables.

       AirCop can be removed from infected diskettes by first powering
       off the system and rebooting from a known clean write protected
       DOS master diskette.  The DOS SYS command should then be used to
       replace the infected diskette's boot sector.  Alternately, MDisk
       can be used following the power-down and reboot.

       Known variant(s) of AirCop include:
       AirCop-B : Submitted in May, 1991 from the United States, AirCop-B is
                  a variant of the original AirCop Virus.  Like the original
                  virus, it only infects floppy disk boot sectors.  The Stack
                  Overflow Error and system halt which occurred on some systems
                  no longer occurs with this variant.  AirCop-B activates
                  during the month of September, when booting from an infected
                  floppy will result in a flashing, scrolling display of the
                  message:

                         "This is Aircop"

                  The boot will then proceed.  AirCop-B has also been altered
                  to avoid detection by anti-viral utilities.  Utilities which
                  can detect AirCop may not be able to detect this variant.


 Virus Name:  Akuku
 Aliases:
 V Status:    Rare
 Discovery:   January, 1991
 Symptoms:    .COM & .EXE growth; "Error in EXE file" message;
              Unexpected drive accesses
 Origin:      USSR
 Eff Length:  891 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Akuku Virus was isolated in January, 1991, and comes from the
       USSR.  This virus is a non-resident direct action infector of .COM and
       .EXE files, including COMMAND.COM.

       When a program infected with Akuku is executed, the virus will infect
       three programs in the current directory.  If three uninfected programs
       cannot be found in the current directory, the virus will search the
       disk directory of the current drive, as well as of the C: drive.
       Both .COM and .EXE programs may become infected, as well as COMMAND.COM.
       Programs smaller than 1K will not be infected by this virus.  Infected
       programs will increase in length by 891 to 907 bytes, the virus will be
       located at the end of the infected file.  The file date and time in the
       disk directory will not be altered by the virus.

       The following text string is contained within the virus's code, and
       can be found in all infected programs:

               "A kuku, Nastepny komornik !!!"

       Some .EXE programs will fail to execute properly after infection by the
       Akuku Virus.  These programs may display an "Error in EXE file"
       message and terminate when the user attempts to execute them.


 Virus Name:  Alabama
 Aliases:
 V Status:    Endangered
 Discovery:   October, 1989
 Symptoms:    .EXE growth, Resident (see text), message, FAT corruption
 Origin:      Israel
 Eff Length:  1,560 bytes
 Type Code:   PRfET - Parasitic Resident .EXE infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  CleanUp, F-Prot, Pro-Scan 1.4+, Scan/D/X, VirHunt 2.0+,
              or delete infected files
 General Comments:
       The Alabama virus was first isolated at Hebrew University in
       Israel by Ysrael Radai in October, 1989.  Its first known
       activation was on October 13, 1989.  The Alabama virus will
       infect .EXE files, increasing their size by 1,560 bytes.  It
       installs itself memory resident when the first program infected
       with the virus is executed, however it doesn't use the normal
       TSR function.  Instead, this virus hooks Int 9 as well as making
       use of IN and OUT commands.  When a CTL-ALT-DEL combination is
       detected, the virus causes an apparent boot but remains in RAM.
       The virus loads itself 30K under the highest memory location
       reported by DOS, and does not lower the amount of memory
       reported by BIOS or DOS.

       After the virus has been memory resident for one hour, the
       following message will appear in a flashing box:

       "SOFTWARE COPIES PROHIBITED BY INTERNATIONAL LAW..............
        Box 1055 Tuscambia ALABAMA USA."

       The Alabama virus uses a complex mechanism to determine whether
       or not to infect the current file.  First, it checks to see if
       there is an uninfected file in the current directory, if there
       is one it infects it.  Only if there are no uninfected files
       in the current directory is the program being executed
       infected.  However, sometimes instead of infecting the
       uninfected candidate file, it will instead manipulate the FATs
       to exchange the uninfected candidate file with the currently
       executed file without renaming it, so the user ends up thinking
       he is executing one file when in effect he is actually
       executing another one.  The end result is that files are
       slowly lost on infected systems.  This file swapping occurs
       when the virus activates on ANY Friday.


 Virus Name:  Alameda
 Aliases:     Merritt, Peking, Seoul, Yale
 V Status:    Rare
 Discovery:   1987
 Symptoms:    Floppy boot failures, Resident-TOM, BSC
 Origin:      California, USA
 Eff Length:  N/A
 Type Code:   RtF - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  MDisk, CleanUp, F-Prot, NAV, or DOS SYS
 General Comments:
       The Alameda virus was first discovered at Merritt college in
       Alameda, California in 1987.  The original version of this virus
       caused no intentional damage, though there is now at least 1
       variant of this virus that now causes floppy disks to become
       unbootable after a counter has reached its limit (Alameda-C
       virus).

       The Alameda virus, and its variants, all replicate when the
       system is booted with a CTL-ALT-DEL and infect only 5 1/4"
       360K diskettes.  These viruses do stay in memory thru a warm
       reboot, and will infect both system and non-system disks.
       System memory can be infected on a warm boot even if Basic is
       loaded instead of DOS.

       The virus saves the real boot sector at track 39, sector 8,
       head 0.  The original version of the Alameda virus would only
       run on a 8086/8088 machine, though later versions can now run
       on 80286 systems.

       Also see: Golden Gate, SF Virus


 Virus Name:  Ambulance Car Virus
 Aliases:     Ambulance, RedX
 V Status:    Rare
 Discovery:   June, 1990
 Symptoms:    .COM growth, graphic display & sound
 Origin:      West Germany
 Eff Length:  796 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method: ViruScan V64+, F-Prot 1.12+, Pro-Scan 2.01+, NAV,
              IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 2.01+, NAV, or Delete infected files
 General Comments:
       The Ambulance Car Virus was isolated in West Germany in June, 1990.
       This virus is a non-resident .COM infector.

       When a program infected with the Ambulance Car Virus is executed,
       the virus will attempt to infect one .COM file.  The .COM file to
       be infected will be located on the C: drive.  This virus only infects
       one .COM file in any directory, and never the first .COM file in
       the directory.  It avoids infecting COMMAND.COM as that file is
       normally the first .COM file in the root directory.

       On a random basis, when an infected file is executed it will
       have the affect of a graphics display of an ASCII block drawing of
       an ambulance moving across the bottom of the system display.  This
       graphics display will be accompanied with the sound of a siren
       played on the system's speaker.  Both of these effects only occur
       on systems with a graphics capable display adapter.


 Virus Name:  Amstrad
 Aliases:     Amstrad 2, S-847, Pixel, Pixel 2
 V Status:    Endangered
 Discovery:   November, 1989
 Symptoms:    .COM growth, message
 Origin:      Portugal
 Eff Length:  847 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC 1.1+,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  Scan/D/X, F-Prot, Pro-Scan 1.4+, or
              delete infected files
 General Comments:
       The Amstrad virus was first reported in November, 1989, by
       Jean Luz of Portugal, however it has been known of in Spain
       and Portugal for a year prior to that.  The virus is a generic
       .COM infector, but is not memory resident nor does it infect
       COMMAND.COM.

       The virus carries a fake advertisement for the Amstrad computer.

       The Amstrad virus appears to cause no other damage to the
       system other than replicating and infecting files.

       Known variants of the Amstrad Virus are:
       Pixel/V-345 - Similar to the Amstrad virus described above, except
                     that the virus is 345 Bytes in length, can now infect
                     COMMAND.COM, and contains the message:
                     "=!= Program sick error:Call doctor or by PIXEL for
                     cure description".  This message is not displayed.
                     The Pixel virus was originally distributed in Greece
                     by Pixel magazine.  The Pixel Virus can only infect
                     programs in the current directory.  This variant may
                     in fact be the original virus in this family, it is
                     rumored that it was released one year before the
                     appearance of the virus in Portugal.
                     Origin: Greece
       Pixel 2     - Similar to other members of this family, this variant was
                     submitted in March 1991 from Europe.  Infected files will
                     increase in size by 850 bytes, with the virus being
                     located at the beginning of the infected program.  This
                     variant contains the same message as Pixel indicated
                     above.
       S-847       - S-847 is the original "dropper" file of the Pixel 2 virus.
                     This program is 384 bytes in length, and when executed
                     will infect all .COM files in the current directory with
                     Pixel 2.
       V-277       - Similar to the Pixel/V-345 virus described above, except
                     that the virus is now 277 Bytes in length, and does not
                     contain any message text.  The original message text
                     has been replaced with code to produce a parity error
                     approximately 50% of the time when an infected program
                     is executed.
                     Origin: Bulgaria
       V-299       - Similar to Pixel, except that the length of the virus
                     is 299 Bytes.
                     Origin: Bulgaria
       V-847       - Similar to Pixel, except that the length of the virus
                     is 847 Bytes.
                     Origin: Bulgaria
       V-847B      - Similar to V-847, except that the message in the virus
                     is now in Spanish and is:
                     "=!= En tu PC hay un virus RV1, y esta es su quinta
                     generacion".
                     This variant was originally distributed by a magazine
                     in Spain in file NOCARGAR.COM.
                     Origin: Spain
       V-852       - Similar to the V-847 variant, this variant does not
                     contain any message.  It infects all .COM files in the
                     current directory whenever an infected program is
                     executed.  If the current directory contains COMMAND.COM,
                     it will be infected as well.  The original sample of this
                     variant received by the author did not contain any text,
                     however after replicating on a test system, all infected
                     files then contained text from the video buffer, which
                     implies the submitted sample was the original distribution
                     of the virus.  This variant checks byte 4 of .COM files
                     to determine if the file was previously infected, if
                     bytes 4-5 are 'SS', the virus assumes the file is already
                     infected.  All infected programs will start with the
                     following hex string, with the nn indicated being a
                     generation number:
                     "EB14905353nn2A2E434F4D004F040000"
                     Origin: Bulgaria


 Virus Name:  Anthrax
 Aliases:
 V Status:    Rare
 Discovery:   July, 1990
 Symptoms:    .COM & .EXE growth
 Origin:      Bulgaria
 Isolated:    Netherlands
 Eff Length:  1040 - 1279 Bytes
 Type Code:   PRAKX - Parasitic Resident .COM, .EXE, & Partition Table Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D + MDisk/P, Pro-Scan 2.01+
 General Comments:
       The Anthrax Virus was isolated in July 1990 in the Netherlands after
       it was uploaded onto several BBSes in a trojan anti-viral program,
       USCAN.ZIP.  It is the second virus to be found in a copy of UScan
       during July 1990, the first virus being V2100.  Anthrax is a memory
       resident generic infector of .COM and .EXE files, including
       COMMAND.COM.

       The first time a program infected with the Anthrax virus is executed
       on the system's hard disk, the virus will infect the hard disk's
       partition table.  At this point, the virus is not memory resident.  It
       will also write a copy of itself on the last few sectors of the
       system's hard disk.  If data existed on those last few sectors of the
       hard disk, it will be destroyed.

       When the system is booted from the hard disk, the Anthrax virus
       will install itself memory resident.  It will remain memory resident
       until the first program is executed.  At that time, it will deinstall
       itself from being resident and infect one .COM or .EXE file.  This
       virus does not infect files in the current directory first, but
       instead starts to infect files at the lowest level of the disk's
       directory tree.

       Later, when an infected program is executed, Anthrax will infect one
       .COM or .EXE file, searching the directory structure from the lowest
       level of the directory tree.  If the executed infected program
       was located on the floppy drive, a .COM or .EXE file may or may not
       be infected.

       The Anthrax Virus's code is 1,024 bytes long, but infected programs
       will increase in length by 1,040 to 1,279 bytes.  On the author's test
       system, the largest increase in length experienced was 1,232 bytes.
       Infected files will always have an infected file length that is a
       multiple of 16.

       The following text strings can be found in files infected with the
       Anthrax virus:

               "(c)Damage, Inc."
               "ANTHRAX"

       A third text string occurs in the viral code, but it is in Cyrillics.
       Per Vesselin Bontchev, this third string translates to: "Sofia 1990".

       Since Anthrax infects the hard disk partition tables, infected systems
       must have the partition table disinfected or rebuilt in order to
       remove the virus.  This disinfection can be done with either a low-
       level format or use of the MDisk/P program for the correct DOS
       version after powering off and rebooting from a write-protected boot
       diskette for the system.  Any .COM or .EXE files infected with
       Anthrax must also be disinfected or erased.  Since a copy of the virus
       will exist on the last few sectors of the drive, these must also be
       located and overwritten.

       Anthrax interacts with another virus: V2100.  If a system which was
       previously infected with Anthrax should become infected with the V2100
       virus, the V2100 virus will check the last few sectors of the hard
       disk for the spare copy of Anthrax.  If the spare copy is found, then
       Anthrax will be copied to the hard disk's partition table.

       It is not known if Anthrax carries any destructive capabilities or
       trigger/activation dates.


 Virus Name:  Anti-Pascal
 Aliases:     Anti-Pascal 605 Virus, AP-605, C-605, V605
 V Status:    Research
 Discovery:   June, 1990
 Symptoms:    .COM growth, .BAK and .PAS file corruption
 Origin:      Bulgaria
 Isolated:    Sofia, Bulgaria
 Eff Length:  605 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan 2.01+, NAV
 Removal Instructions: Pro-Scan 2.01+, Scan/D/X, NAV, or delete infected files
 General Comments:
       The Anti-Pascal Virus, V605 or C-605, was isolated in Sofia,
       Bulgaria in June 1990 by Vesselin Bontchev.  Originally, it was
       thought that the Anti-Pascal virus was from the USSR or Poland,
       but it has since been determined to have been a research virus
       written in Bulgaria over one year before it was isolated.  The
       author was not aware that it had "escaped" until July, 1990.

       The Anti-Pascal Virus is a generic .COM file infector, including
       COMMAND.COM.  While this virus is not memory resident, when it is
       in the process of infecting files, interrupt 24 will be hooked.

       When a program infected with the Anti-Pascal virus is executed,
       the virus will attempt to infect two other .COM files on the
       current drive or on drive D: which are between 605 and 64,930
       bytes in length.  These files must not have the read only
       attribute set.  If an uninfected .COM file meeting the virus's
       selection criteria is found, the first 605 bytes of the program
       is overwritten with the viral code.  The original 605 bytes of
       the program is then appended to the end of the infected file.
       Infected files will have increased in length by 605 bytes, and
       they will also begin with the text string "PQVWS" as well as
       contain the string "combakpas???exe" at offset 0x17.  Infected
       files will also have had their file date/time stamps in the
       directory updated to the date/time that the infection occurred.

       If the Anti-Pascal Virus cannot find two .COM files to infect,
       it will check the current drive and directory for .BAK and .PAS
       files.  If these files exist, they will be overwritten with the
       virus's code.  If the overwritten files were .PAS files, the
       system's user has now lost some of their Pascal source code.
       After overwriting .BAK and .PAS files, the virus will attempt to
       rename them to .COM files, or .EXE files if a .COM file already
       exists.  This rename does not work due to a bug in the virus.

       Known variant(s) of the Anti-Pascal Virus are:
       AP-529    : Similar to the 605 byte Anti-Pascal Virus, the major
                   differences are that AP-529 will only infect .COM files
                   over 2,048 bytes in length.  Infected files increase in
                   length by 529 bytes.  Additionally, instead of overwriting
                   the .BAK and .PAS files, one .BAK and .PAS file will be
                   deleted if there are no uninfected .COM files with a
                   length of at least 2,048 bytes on the current drive.
                   .COM files on the C: drive root directory may also be
                   infected by AP-529 when it is executed from the A: or B:
                   drive.  This variant should be considered a "Research
                   Virus", it is not believed to have been publicly
                   released.

       Also see: Anti-Pascal II


 Virus Name:  Anti-Pascal II
 Aliases:     Anti-Pascal 400, AP-400
 V Status:    Research
 Discovery:   June, 1990
 Symptoms:    .COM growth; .BAK, .BAT and .PAS file deletion, boot sector
              alteration on hard disk
 Origin:      Bulgaria
 Isolated:    Sofia, Bulgaria
 Eff Length:  400 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan 2.01+, NAV
 Removal Instructions: Pro-Scan 2.01+, Scan/D/X, or delete infected files
 General Comments:
       The Anti-Pascal II Virus, or AP-400, was isolated in Sofia,
       Bulgaria in June 1990 by Vesselin Bontchev.  It is one of five
       viruses/variants in the Anti-Pascal family.  Two of the earlier
       variants, Anti-Pascal/AP-605 and AP-529, are documented under
       the name "Anti-Pascal".  The variants listed under Anti-Pascal II
       have been separated due to some of their characteristics differing
       from the 605 byte and 529 byte viruses.

       The Anti-Pascal II Virus is a generic .COM file infector, including
       COMMAND.COM.  While this virus is not memory resident, when it is
       in the process of infecting files, interrupt 21 will be hooked.

       The first time a program infected with the Anti-Pascal II virus is
       executed on a system, the virus will attempt to infect one (1)
       .COM file in the root directory of each drive accessible on the
       system.  Files are only infected if their length is at least 2,048
       bytes, and the resulting infected file will be less than 64K in
       length.  Since COMMAND.COM is usually the first .COM file on a
       drive, it will immediately become infected.  One additional .COM
       file will also be infected on the current drive.  The mechanism used
       to infect the file is to write the virus's code to the end of the
       file.  A jump is used to execute the virus's code before the original
       program is executed.  Infected files do not have their date/time
       stamps in the directory updated to the system date and time when the
       infection occurred.

       If the Anti-Pascal Virus cannot find a .COM file to infect on a
       given drive, or two .COM files to infect on the current drive,
       it will check for the existence of .BAK, .PAS, or .BAT files.  If
       found, these files will be deleted.  These deletions only occur in
       root directories and on the current drive's current directory.  Since
       each root directory (as well as the current directory) will typically
       not have all of its .COM files infected at the same time, the deletes
       will occur on different drives and directories at different times.

       Symptoms of infection of the Anti-Pascal II Virus include file length
       increases of 400 bytes, unexpected disk access to drives other than
       the current drive, and disappearing .BAK, .PAS, and .BAT files.  One
       other symptom of an Anti-Pascal II infection is that the hard disk's
       boot sector will be slightly altered by the virus.  Anti-viral programs
       which CRC-check the boot sector will indicate that a boot sector
       infection may have occurred.  The boot sector alteration does not
       contain a live virus, but will throw the system user off into thinking
       their problem is from a boot sector virus instead of a file infector,
       and if the disk as a bootable disk, it will not be unbootable.

       The Anti-Pascal II Virus and its variants indicated below are not
       believed to have been publicly released.  As such, they have been
       classified as "Research Viruses".

       Known variant(s) of the Anti-Pascal II Virus are:
       AP-440    : Very similar to the 400 byte version of the Anti-Pascal II
                   Virus, the major characteristic change is that this
                   variant has a length of 440 bytes.  The boot sector is no
                   longer altered by the virus.  This variant is an
                   intermediary between AP-480 and the 400 byte version
                   documented above.
       AP-480    : Similar to the Anti-Pascal II virus, this variant is the
                   version which is 480 bytes in length.  It does not
                   delete .BAT files, but only .BAK and .PAS.  This variant
                   is the latest variant of the Anti-Pascal II grouping.

       Also see: Anti-Pascal


 Virus Name:  AntiChrist
 Aliases:
 V Status:    Research
 Discovery:   March, 1991
 Symptoms:    .EXE growth; decrease in total system and available free memory
 Origin:      Italy
 Eff Length:  1,008 Bytes
 Type Code:   PRhE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan V76+, IBM Scan 2.00+
 Removal Instructions: CleanUp V77+, or Delete Infected Files
 General Comments:
       The AntiChrist Virus was submitted in March, 1991, by David Grant of the
       United States, whom received it from Italy.  This virus is a memory
       resident infector of .EXE files, and is related to the Murphy Virus
       from Bulgaria.

       The first time a program infected with AntiChrist is executed, the
       virus will install itself memory resident at the top of system memory
       but below the 640K DOS boundary.  Interrupt 12's return is not moved.
       Total system memory, and available free memory, as indicated by the
       DOS ChkDsk program will decrease by 1,040 bytes.  Interrupt 21 is
       hooked by the virus.

       After AntiChrist is memory resident, it will infect .EXE programs
       greater than 1K in length when they are executed or openned for any
       reason.  Infected programs will have a file length increase of 1,008
       bytes, the virus will be located at the end of the infected file.  The
       disk directory date and time will not be altered.

       Of the two samples submitted, one was not a natural infection of
       AntiChrist as it was on a .COM program.  This virus may be a research
       virus and not in the public domain at the time it was submitted.

       Also see: Murphy


 Virus Name:  Arf
 Aliases:     Rigor Mortis, Thor
 V Status:    Rare
 Discovery:   March, 1991
 Symptoms:    .COM growth; Messages
 Origin:      United States
 Eff Length:  1,000 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  Scan V75+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Arf, Thor, or Rigor Mortis Virus was submitted in March, 1991 from
       the United States.  This virus is a non-resident infector of .COM
       files, including COMMAND.COM.  Arf is based on the Vienna Virus, and
       some anti-viral programs may identify it as Vienna.

       When a program infected with Arf is executed, the virus will check to
       see if COMMAND.COM has been previously infected.  If it is not infected,
       the virus will infect it and display the message:

               "Rigor Mortis !!!
                  I am Hi.pas"

       After checking (and possibly infecting) COMMAND.COM, the virus will
       search the current directory for one .COM program to infect.  If an
       uninfected .COM program is found, it will be infected with the following
       message being displayed:

               "Arf krad krad krad
                  krad krad kr"

       The virus will then proceed to check the B: drive for a file to infect.

       Files infected with the Arf virus will have a file length increase of
       1,000 bytes.  The virus will be located at the end of the infected
       program.  The above text messages can be found within the infected
       files.

       The Arf Virus may not be in the public domain, the original sample
       submitted is not a natural infection of the virus.  Its name is due to
       the "Arf" string displayed when files other than COMMAND.COM are
       infected.  Its alias of Thor is because it is believed to have been
       written by a group calling itself Thor.

       Note: the original sample of this virus was on an .EXE file, and is
       not a natural infection.  This virus may be a research virus and not
       in the public domain.

       Known variant(s) of Arf include:
       Arf-B   : Arf-B was submitted in May, 1991.  It is from the United
                 States.  This variant appears to be an earlier version of the
                 Arf Virus described above.  When a program infected with
                 Arf-B is executed, it will check the current directory for
                 an uninfected .COM program to infect.  If an uninfected .COM
                 program is found, it will infect the program.  The B: drive
                 may also be accessed.  Whether or not a program was infected,
                 it will then display the message:

                       "Arf Arf Got you!
                        -- RABID '90"

                 Infected programs will have a file length increase of 1,000
                 bytes, and their date and time in the disk directory will be
                 altered, though not to the current system date and time.

                 Execution of COMMAND.COM after it has become infected will
                 result in the following messages, and a system hang:

                       "EXEC failure
                        Memory allocation error
                        Cannot start COMMAND, exiting"

                 .COM programs infected with Arf-B will usually fail to
                 function once infected, resulting in a system hang.


 Virus Name:  Armagedon
 Aliases:     Armagedon The First, Armagedon The Greek
 V Status:    Rare
 Discovery:   June, 1990
 Symptoms:    text string intermittently sent to COM ports
 Origin:      Athens, Greece
 Eff Length:  1,079 Bytes
 Type Code:   PRC - Parasitic Resident .COM Infector
 Detection Method: ViruScan V64+, F-Prot 1.12+, Pro-Scan 2.01+, NAV,
              IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, or Delete infected files
 General Comments:
       The Armagedon virus was isolated on June 2, 1990, by George
       Spiliotis of Athens, Greece.  Armagedon is a memory resident
       virus which infects .COM files, increasing their length by 1,079
       bytes.

       The first time an infected program is executed on a system, the
       virus installs itself memory resident, hooking interrupts 8 and 21.
       Any .COM files which are later executed are then infected by the
       resident virus.

       Infected systems will experience the text string "Armagedon the GREEK"
       being sent to COM ports 1 - 4 at time intervals.  Between 5:00 and
       7:00, the virus will attempt to use the system's COM ports to make
       a phone call to Local Time Information in Crete, Greece.  If a
       connection is made, the phone line will remain open until the user
       notices that the phone line is in use.  (Needless to say, this
       doesn't work if the system is located outside of Greece as dialing
       codes are considerably different between countries.)

       This virus otherwise is not destructive.


 Virus Name:  Ashar
 Aliases:     Shoe_Virus, UIUC Virus
 V Status:    Common
 Discovery:
 Symptoms:    BSC, Resident TOM
 Origin:
 Eff Length:  N/A
 Type Code:   BRt - Resident Boot Sector Infector
 Detection Method:  ViruScan V41+, F-Prot, IBM Scan, Pro-Scan 1.4+, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  MDisk, CleanUp, Pro-Scan 1.4+, F-Prot, NAV, or
              DOS SYS command
 General Comments:
       The Ashar virus is a resident boot sector infector which is
       a variant of the Brain virus.  It differs from the Brain
       virus in that it can infect both floppies and hard disk, and
       the message in the virus has been modified to be:

            "VIRUS_SHOE RECORD, v9.0.  Dedicated to the dynamic
            memories of millions of virus who are no longer with us
            today".

       However, the above message is never displayed.  The
       identification string "ashar" is normally found at offset
       04a6 hex in the virus.

       A variant of the Ashar virus exists, Ashar-B or Shoe_Virus-B,
       which has been modified so that it can no longer infect hard
       drives.  The v9.0 in the message has also been altered to v9.1.

       Also see: Brain


 Virus Name:  Attention!
 Aliases:     USSR 394
 V Status:    Rare
 Discovery:   December, 1990
 Symptoms:    .COM file growth; decrease in system and available memory;
              clicking emitted from system speaker on keypress; file date/time
              changes
 Origin:      USSR
 Eff Length:  394 Bytes
 Type Code:   PRhCK - Parasitic Resident .COM  Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Attention! Virus was submitted in December, 1990 and was originally
       isolated in the USSR.  This virus is a memory resident infector of COM
       files, including COMMAND.COM.

       The first time a program infected with the Attention! Virus is executed,
       the virus will reserve 416 bytes at the top of system memory but below
       the 640K DOS boundary.  The virus becomes memory resident in this area,
       and hooks interrupt 21.  Total system memory and available free memory
       returned by the DOS ChkDsk command will decrease by 416 bytes.  The
       interrupt 12 return is not moved.

       After the virus is memory resident, a clicking sound will be emitted
       by the system speaker each time a key is pressed on the keyboard.  Some
       programs, such as the Edlin program supplied with MS-DOS, will receive
       an "Invalid drive or file name" message when they are attempted to be
       executed.

       Attention! will infect COM files, including COMMAND.COM, when they are
       executed.  The exception is that very small COM files will not become
       infected.  Infected files will increase in length by 394 bytes with the
       virus being located at the end of the file.  Infected programs will also
       contain the text string: "ATTENTION  !" near the beginning of the
       program.


 Virus Name:  Australian 403
 Aliases:
 V Status:    Rare
 Discovery:   February, 1991
 Symptoms:    .COM files become 403 bytes in length; TSR;
              File date/time changes; .COM files do not function properly
 Origin:      Australia
 Eff Length:  403 Bytes
 Type Code:   PRsCK - Parasitic Resident .COM Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The Australian 403 Virus was submitted in February, 1991 by Colin Keeble
       of Australia.  This virus is a memory resident infector of .COM files,
       including COMMAND.COM.

       The first time a program infected with the Australian 403 Virus is
       executed, the virus will install itself memory resident as a low system
       memory TSR of 720 bytes.  The virus will hook interrupt 21.

       Once the virus is memory resident, the virus will replace two .COM
       programs in the current directory with a copy of the virus each time
       any program is executed.  The replaced programs will have a file length
       of 403 bytes, and their date and time in the disk directory will have
       been altered to the system date and time when infection occurred.
       Needless to say, the replaced programs will not execute properly since
       they now only contain the virus's code.

       This virus does not do anything besides replicate.


 Virus Name:  Azusa
 Aliases:     Hong Kong
 V Status:    Rare
 Discovery:   February, 1991
 Symptoms:    BSR; Decrease in total system and available free memory;
              LPT1 & COM1 ports may be disabled
 Origin:      Hong Kong
 Eff Length:  N/A
 Type Code:   BRtX - Resident Boot Sector & Partition Table Infector
 Detection Method:  ViruScan V75+
 Removal Instructions: Clean-Up V75+
 General Comments:
       The Azusa Virus was received in February, 1991.  Its origin is unknown,
       though its origin is believed to be Hong Kong.  This virus is a memory
       resident infector of diskette boot sectors and the hard disk partition
       table.

       The first time the system is booted from a diskette infected with the
       Azusa Virus, the virus will become memory resident at the top of
       system memory, but below the 640K DOS boundary.  The virus moves the
       Interrupt 12 return so that the system will report 1,024 Bytes less
       memory than is installed on the system.  At this time, the virus will
       infect the system's hard disk partition table, overwriting the
       partition table with a copy of the Azusa virus.  A copy of the original
       partition table is not stored by the virus.

       Once Azusa is memory resident, it will infect diskettes when they are
       accessed on the system with write intent (ie: a file is openned as
       output, or with read/write intent) or when attempting to reboot the
       system from a diskette via CTL-ALT-DEL.  Diskettes are infected by
       copying the original diskette boot sector to track 40 sector 8, and
       then writing a copy of itself to the diskette's boot sector.  On
       diskettes other than 360K 5.25" diskettes, the original boot sector
       will end up in the middle of the disk, possibly corrupting files.

       The Azusa Virus keeps track of how many times the system has been
       booted from an infected diskette.  After 32 boots, the virus will
       disable the COM1 and LPT1 ports on the system, and reset its counter.
       A later boot will result in the ports functioning properly again.

       Known variant(s) of Azusa include:
       Azusa 2 : Submitted in April, 1991, this variant is from Hong Kong.
                 The memory resident portion of Azusa 2 is 2,048 bytes in
                 length, located at the top of system memory but below the
                 640K DOS boundary.  Infection of high-density diskettes will
                 result in severe cross-linking of files and invalid clusters,
                 as well as 0 bytes in directories.  Ctrl-C may fail to
                 function, as well as boots from infected diskettes may hang
                 the system.  Disabling of COM1 and LPT1 may also be
                 experienced.

       Also see: Evil Empire


 Virus Name:  Best Wishes
 Aliases:     Best Wish
 V Status:    Rare
 Discovery:   December, 1990
 Symptoms:    .COM file growth; decrease in system and available free memory;
              system hangs; file date/time changes; file not found errors;
              boot sector modification
 Origin:      USSR
 Eff Length:  970 Bytes
 Type Code:   PRtCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Best Wishes Virus was submitted in December, 1990 and is believed
       to be from the USSR.  Best Wishes is a memory resident infector of
       COM files, including COMMAND.COM.  There is a variant of this virus,
       Best Wishes B, which is 1,024 bytes in length.

       The first time a program infected with the Best Wishes Virus is
       executed, the virus will install itself memory resident in system high
       memory, but below the 640K DOS boundary.  The interrupt 12 return will
       be moved.  Total system memory will decrease by 61,440 bytes, available
       free memory will decrease by 61,360 bytes.  COMMAND.COM will become
       infected at this time, and the disk's boot sector will also be modified.
       Disks with the boot sector modification and infected COMMAND.COM will
       still boot properly.

       After Best Wishes is resident, the virus will infect COM files as they
       are executed with a probability of 50%.  Infected COM files will
       increase in length by 970 bytes with the virus being located at the
       end of the infected file.  Infected programs will also have the following
       text string located near the end of the file:

               "This programm ... With Best Wishes!"

       Best Wishes does not restore the original file date and time in the
       directory when it infects programs, so all infected programs will have
       their date/time stamps set to the system date and time when infection
       occurred.

       Two additional symptoms of a Best Wishes infection are that the user
       may experience "File not found" errors when the file is actually on
       disk, as well as system hangs on every fourth program execution.

       Known variant(s) of Best Wishes are:
       Best Wishes B - An earlier version of Best Wishes, this variant is
             1,024 bytes in length.  The major differences are that infected
             disks will not boot if COMMAND.COM has been modified.  Execution
             of a COM program once the virus is memory resident will result in
             the program most likely being infected, but the system will also
             become hung.


 Virus Name:  Black Monday
 Aliases:
 V Status:    Rare
 Discovery:   September, 1990
 Symptoms:    .COM & .EXE file growth; TSR; file timestamp changes
 Origin:      Kuala Lumpur, Malaysia
 Eff Length:  1,055 Bytes
 Type Code:   PRsAK - Parasitic Resident .COM & .EXE Infector
 Detection Method: ViruScan V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: Pro-Scan 2.01+, CleanUp V77+, Delete infected files
 General Comments:
       The Black Monday Virus was isolated in Fiji in September, 1990.  It
       is reported to be widespread in Fiji and other locations in the Far
       East and Asia.  This virus is a memory resident generic infector of
       .COM and .EXE files, including COMMAND.COM.

       The first time a program infected with the Black Monday Virus is
       executed, the virus will install itself memory resident as a low
       system memory TSR of 2,048 bytes.  Interrupt 21 will be hooked by
       the virus.

       Once the virus is memory resident, any program which is executed
       will become infected with the Black Monday Virus.  .COM files will
       increase in length by 1,055 bytes with the virus's code located at
       the end of the infected files.  .EXE files will also increase in
       length by 1,055 bytes with the virus's code added to the end of
       the file.  This virus does not infect .EXE files multiple times.

       The virus does not hide the change in file length when the directory
       is displayed, though a directory display will indicated that the
       infected file's date/timestamp have been updated to the system date
       and time when the file was infected.

       The following text string can be found in all infected files near
       the beginning of the virus's code:

               "Black Monday 2/3/90 KV KL MAL"

       It is unknown when Black Monday activates, or what it does at
       activation.


 Virus Name:  Blood
 Aliases:     Blood2
 V Status:    Rare
 Discovery:   August, 1990
 Symptoms:    .COM file length increase, system reboots and/or hangs,
              cascading screen effect
 Origin:      Natal, Republic of South Africa
 Eff Length:  418 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method: Pro-Scan 2.0+, ViruScan V75+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Blood Virus was submitted by Fridrik Skulason in August, 1990.
       It was originally isolated in Natal, Republic of South Africa.  There
       are two variants of this virus, Blood and Blood2.  This virus is a
       non-resident infector of .COM files, including COMMAND.COM.

       When a program infected with the Blood virus is executed, it will
       infect one .COM file located in the C: drive root directory.  The
       newly infected file will have increased in length by 418 bytes.  If
       the program just infected is COMMAND.COM, a system reboot will
       occur.  Following the system reboot, executing an infected program
       will result in a cascading effect of the cursor down the screen.  The
       next .COM file executed will then result in the hard disk being
       accessed followed by the system hanging.  Spurious characters from
       memory may also appear on the screen on the line below the command
       line.

       After August 15, execution of an infected program will result in a
       system hang.

       Known variant(s) of Blood are:
       Blood2 : Similar to Blood, with the major difference being that
                system reboots, system hangs, and the cascading cursor
                effect no longer occur.  This variant also does not hang
                the system after August 15.


 Virus Name:  Bloody!
 Aliases:
 V Status:    Rare
 Discovery:   December, 1990
 Symptoms:    Extended boot time; decrease in system & available memory;
              message on boot; boot sector & partition table changes
 Origin:      Taiwan
 Eff Length:  N/A
 Type Code:   BRtX - Resident Boot Sector & Partition Table Infector
 Detection Method:  ViruScan V72+
 Removal Instructions:  See below
 General Comments:
       The Bloody! Virus was submitted in December 1990, and infection
       reports were received from Europe, Taiwan, and the United States.  This
       virus is a memory resident infector of floppy diskette boot sectors as
       well as the hard disk partition table.

       When a system is booted from a floppy or hard disk infected with the
       Bloody! Virus, the virus will install itself memory resident at the
       top of system memory but below the 640K DOS boundary.  Total system
       memory and available free memory will decrease by 2,048 bytes.  The
       interrupt 12 return will be moved.  The system boot will also take
       much longer than expected.  The system's hard disk's partition table
       will become infected immediately if it was not the source of the
       system boot.

       At the time of system boot, the virus also maintains a counter of how
       many times the infected diskette or hard drive has been booted.  Once
       128 boots have occurred, the virus will display the following message
       during the boot:

               "Bloody! Jun. 4, 1989"

       June 4, 1989 is the date of the the confrontation in Beijing, China
       between Chinese students and the Chinese Army in which many students
       were killed.

       This message will later be displayed on every sixth boot once the
       128 boot limit has been reached.  The text message is encrypted within
       the viral code, so it is not visible in the boot sector.

       Once Bloody! is memory resident, the virus will infect any diskette
       or hard disk when a file or program is accessed.  Listing a disk
       directory will not be enough to cause the virus to infect the disk.

       Infected diskette boot sectors will be missing all of the normal
       DOS error messages which are normally found in the boot sector.  The
       original boot sector will have been moved to sector 11 on 360K diskettes,
       a part of the root directory.  If there were previously root directory
       entries in that sector, those files will be lost.

       On the hard disk, the original partition table will have been moved
       to side 0, cylinder 0, sector 6.

       For floppies of other sizes then 360K, they may become unusable or
       corrupted as the virus does not take into account the existence of these
       disk types.

       For diskettes, Bloody! can be removed by powering the system off and
       then booting from a known-clean, write protected original DOS diskette.
       The DOS SYS command should then be executed on each of the infected
       diskettes.

       To remove the Bloody! Virus from the hard disk's partition table, the
       original partition table should be located and then copied back to
       its original position.  The other option is to backup the files on
       the hard disk and low level format the drive.


 Virus Name:  Brain
 Aliases:     Pakistani, Pakistani Brain
 V Status:    Common
 Discovery:   1986
 Symptoms:    Extended boot time, Volume label change, Resident TOM,
              Three contiguous bad sectors (floppy only), BSC
 Origin:      Pakistan
 Eff Length:  N/A
 Type Code:   BRt - Resident Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  MDisk, CleanUp, F-Prot, Pro-Scan, NAV, or
              DOS SYS command
 General Comments:
       The Pakistani Brain virus originated in Lahore, Pakistan and
       infects disk boot sectors by moving the original contents of the
       boot sector to another location on the disk, marking those 3
       clusters (6 sectors) bad in the FAT, and then writing the virus
       code in the disk boot sector.

       One sign of a disk having been infected, at least with the
       original virus, is that the volume label will be changed
       to "(c) Brain".  Another sign is that the label "(c) Brain" can
       be found in sector 0 (the boot sector) on an infected disk.

       This virus does install itself resident on infected systems,
       taking up between 3K and 7K of RAM.  The Brain virus is able to
       hide from detection by intercepting any interrupt that might
       interrogate the boot sector and redirecting the read to the
       original boot sector located elsewhere on the disk, thus some
       programs will be unable to see the virus.

       The original Brain virus only infected floppies, however variants
       to the virus can now infect hard disks.  Also, some variants
       have had the "(c) Brain" label removed to make them harder to
       detect.

       Known variants of the Brain virus include:
       Brain-B/Hard Disk Brain/Houston Virus - hard disk version.
       Brain-C - Brain-B with the "(c) Brain" label removed.
       Clone Virus - Brain-C but restores original boot copyright label.
       Clone-B - Clone Virus modified to destroy the FAT after 5/5/92.

       Also see: Ashar


 Virus Name:  Burger
 Aliases:     541, 909090h, CIA
 V Status:    Extinct
 Discovery:   1986
 Symptoms:    Programs will not run after infection
 Origin:      West Germany
 Eff Length:  560 Bytes
 Type Code:   ONAK - Overwriting Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan /D, or delete infected files
 General Comments:
       The Burger, or 909090h, Virus was written and copyrighted in 1986 by
       Ralf Burger of West Germany.  This virus is extinct in the "public
       domain".  This virus is a non-resident overwriting virus, infecting
       .COM and .EXE files, including COMMAND.COM.

       When a program infected with the Burger Virus is executed, the virus
       will attempt to infect one previously uninfected .COM file located in
       the C: drive root directory.  To determine if the program was previously
       infected, the virus checks to see if the first three bytes of the .COM
       file are three NOP instructions (909090h).  If the first three bytes are
       the NOP instructions, the virus goes on checking until it finds an
       uninfected .COM file.  If no uninfected .COM file exists, the virus
       then renames all the .EXE files in the root directory to .COM files and
       checks those files.  Once it finds a .COM file to infect, it overwrites
       the first 560 bytes of the uninfected program with the virus code.  At
       this point, the program the user was attempting to run will either
       end or hang the system.  Infected programs will never execute properly
       as the first portion of the program has been destroyed.

       Systems which have been infected with the Burger Virus will fail to
       boot once the virus has infected the hard disk boot partition's
       COMMAND.COM, or the copy of COMMAND.COM on their boot diskette.

       Infected files can be easily identified by the "909090B8000026A245"
       hex sequence located in the first nine bytes of all infected files.
       Infected files cannot be disinfected, they must be replaced from a
       clean source.

       Known variant(s) of the Burger virus include:
       CIA     : Discovered in the United States in October, 1990, this virus
                 is similar to the Burger Virus described above.  The first
                 nine bytes of all infected files in hex will be:
                 "909090B8000026A3A5".   The actual length of this variant
                 is 541 bytes, though the first 560 bytes of infected programs
                 are overwritten.
       505     : Similar to the Burger virus, this variant's actual code length
                 is 505 bytes, though the first 560 bytes of infected files
                 will be overwritten.  Infected files will have their first
                 nine bytes contain the hex string: "909090B8000026A3A0".
       509     : Similar to the Burger virus, this variant's actual code length
                 is 509 bytes, though the first 560 bytes of infected files
                 will be overwritten.  Infected files will have their first
                 nine bytes contain the hex string: "909090B8000026A3A4".
       541     : Similar to the Burger virus, this variant overwrites the
                 first 560 bytes of infected programs, though the virus's
                 length is actually 541 bytes.  Infected programs will start
                 with the hex sequence: "909090B8000026A3A4".

       Also see: VirDem


 Virus Name:  Carioca
 Aliases:
 V Status:    Rare
 Discovery:   November, 1990
 Symptoms:    TSR; .COM growth
 Origin:
 Eff Length:  951 Bytes
 Type Code:   PRsC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 2.01+, or Delete Infected Files
 General Comments:
       The Carioca Virus was submitted in November, 1990.  This virus is a
       memory resident infector of .COM files, it does not infect COMMAND.COM.

       The first time a program infected with the Carioca Virus is executed,
       the virus will install itself memory resident as a 1,280 byte low
       system memory TSR.  Interrupt 21 will be hooked by the virus.  The
       system's available free memory will decrease by 1,312 bytes.

       After the virus is memory resident, any .COM file executed (with the
       exception of COMMAND.COM) will become infected with the Carioca
       Virus.  Infected .COM files will show an increase in size of 951 bytes
       with the virus being located at the end of the infected file.  Infected
       files will have the following hex character string located at the
       very end of the file: "2EFF1E1A010203CD21".

       It is unknown if Carioca contains any damage potential.


 Virus Name:  Cascade
 Aliases:     Fall, Falling Letters, 1701, 1704
 V Status:    Common
 Discovery:   October, 1987
 Symptoms:    TSR, Falling letters, .COM file growth
 Origin:      Germany
 Eff Length:  1,701 or 1,704 bytes
 Type Code:   PRsC - Parasitic Resident Encrypting .COM Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  CleanUp, F-Prot, VirexPC, VirHunt 2.0+, Pro-Scan 2.01+
 General Comments:
       Originally, this virus was a trojan horse which was disguised
       as a program which was supposed to turn off the number-lock
       light when the system was booted.  The trojan horse instead
       caused all the characters on the screen to fall into a pile
       at the bottom of the screen.  In late 1987, the trojan horse
       was changed by someone into a memory resident .COM virus.

       While the original virus had a length of 1,701 bytes and would
       infect both true IBM PCs and clones, a variation exists of
       this virus which is 3 bytes longer than the original virus
       and does not infect true IBM PCs.  Both viruses are
       functionally identical in all other respects.

       Both of the viruses have some fairly unique qualities:  Both
       use an encryption algorithm to avoid detection and complicate
       any attempted analysis of them.  The activation mechanisms
       are based on a sophisticated randomization algorithm
       incorporating machine checks, monitor types, presence or
       absence of a clock card, and the time or season of the year.

       The viruses will activate on any machine with a CGA or VGA
       monitor in the months of September, October, November, or
       December in the years 1980 and 1988.

       Known variants of the Cascade virus are:
       1701-B : Same as 1701, except that it can activate in the
                fall of any year.
       1704-D : Same as the 1704, except that the IBM selection
                has been disabled so that it can infect true IBM
                PCs.
       17Y4   : Similar to the Cascade 1704 virus, the only difference is
                one byte in the virus which has been altered.
       Cunning: Based on the Cascade virus, a major change to the virus
                is that it now plays music.

       Also see: 1704 Format


 Virus Name:  Cascade-B
 Aliases:     Blackjack, 1704-B
 V Status:    Common
 Discovery:
 Symptoms:    .COM file growth, TSR, random reboots
 Origin:      Germany
 Eff Length:  1,704 bytes
 Type Code:   PRsC - Parasitic Resident Encrypting .COM Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, VirexPC, AVTK 3.5+, Pro-Scan,
              VirHunt 2.0+, NAV
 Removal Instructions:  CleanUp, F-Prot, VirexPC, VirHunt 2.0+
 General Comments:
       The Cascade-B virus is similar to the Cascade virus, except
       that the cascading display has been replaced with a system
       reboot which will occur at random time intervals after the
       virus activates.

       Other variation(s) which have been documented are:
       1704-C : Same as 1704-B except that the virus can activate in
                December of any year.


 Virus Name:  Casino
 Aliases:
 V Status:    Rare
 Discovery:   April, 1991
 Symptoms:    .COM growth; decrease in total system & available free memory;
              File allocation errors
 Origin:      Unknown
 Eff Length:  2,330 bytes
 Type Code:   PRhCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V77+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Casino Virus was submitted in April, 1991 by David Chess of IBM.
       This virus is a memory resident infector of .COM files, including
       COMMAND.COM.

       The first time a program infected with Casino is executed, Casino will
       install itself memory resident at the top of system memory.  Total
       system and available free memory, as indicated by the DOS ChkDsk
       program will decrease by 37,568 to 37,632 bytes.  3,152 bytes in low
       system memory will also be used by the virus, and interrupts 00, 23,
       and 30 will point to this area.  After Casino is resident, it will
       then immediately infect COMMAND.COM located in the C: drive root
       directory.

       After Casino is memory resident, it will infect .COM programs when
       any of three events occur.  If the system user issues a DIR command,
       or a program does an internal DIR command, one .COM file in the
       current directory will be infected.  Additionally, if the system user
       executes an infected program, a .COM program will become infected.
       Lastly, Casino will infect .COM programs that are openned by another
       program for any reason.

       Programs infected with Casino will have a file length increase of
       2,332 to 2,346 bytes.  The file length increase, however, is mostly
       hidden if the virus is memory resident.  With the virus memory resident,
       infected files will have a file length increase of 1 to 16 bytes, but
       occasionally one may show a file length increase of up to 48 bytes.
       The virus does not alter the file date and time in the disk directory.

       If Casino is memory resident and the DOS ChkDsk program is executed,
       file allocation errors will be returned for each infected program.  If
       the ChkDsk /F option is used, program corruption will occur.

       It is unknown if Casino does anything besides replicate.


 Virus Name:  Casper
 Aliases:
 V Status:    Rare
 Discovery:   August, 1990
 Symptoms:    .COM file growth, April 1st disk corruption (see below)
 Origin:
 Eff Length:  1,200 bytes
 Type Code:   PNCK - Parasitic Non-Resident Encrypting .COM Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, NAV, or Delete infected files
 General Comments:
       The Casper Virus was isolated in August, 1990 by Fridrik Skulason of
       Iceland.  The origin of this virus is unknown at this time.  Casper
       is a non-resident generic infector of .COM files, including COMMAND.COM.

       When a program infected with the Casper Virus is executed, the virus
       will attempt to infect one .COM program located in the current drive
       and directory.  Infected files will increase in length by 1,200 bytes,
       with the virus's code being located at the end of the .COM file.

       The Casper Virus contains the following message, though this message
       cannot be seen in infected program as Casper uses a complex self-
       encryption mechanism:

             "Hi! I'm Casper The Virus, And On April 1st I'm Gonna
              Fuck Up Your Hard Disk REAL BAD! In Fact It Might Just
              Be Impossible To Recover! How's That Grab Ya! <GRIN>"

       On April 1st, when an infected program is executed, this virus will
       overwrite the first track of the drive where the infected program was
       executed from.  Later attempts to access the drive will result in
       "Sector not found" errors occurring.

       The Casper Virus is based on the Vienna virus.  Unlike Vienna, it is
       self-encrypting.  The self-encryption mechanism employed is similar
       to the encryption mechanism used in the V2P6 virus, and requires an
       algorithmic approach in order to identify it as there are not any
       identifying strings located in the encrypted virus.


 Virus Name:  Chaos
 Aliases:
 V Status:    Rare
 Discovery:   December, 1989
 Symptoms:    Message, TSR, Bad sectors, BSC
 Origin:      England
 Eff Length:  N/A
 Type Code:   BR - Resident Boot Sector Infector
 Detection Method:  ViruScan V53+
 Removal Instructions:  MDisk, CleanUp, or DOS SYS Command
 General Comments:
       First reported in December, 1989 by James Berry of Kent,
       England, the Chaos virus is a memory resident boot sector
       infector of floppy and hard disks.

       When the Chaos virus infects a boot sector, it overwrites the
       original boot sector without copying it to another location
       on the disk.  Infected boot sectors will contain the
       following messages:

            "Welcome to the New Dungeon"
            "Chaos"
            "Letz be cool guys"

       The Chaos virus will flag the disk as being full of bad
       sectors upon activation, though most of the supposed bad
       sectors are still readable.  It is unknown what the
       activation criteria is.


 Virus Name:  Christmas In Japan
 Aliases:     Xmas In Japan, Japanese Christmas
 V Status:    Rare
 Discovery:   September, 1990
 Symptoms:    .COM file growth; Message
 Origin:      Taiwan
 Eff Length:  600 Bytes
 Type Code:   PNCK - Resident Non-Resident .COM Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The Christmas In Japan Virus was isolated in Taiwan in late September,
       1990.  As of early October, it is reported to be widespread in Japan.
       This virus is a 600 byte non-resident generic infector of .COM files.
       It will infect COMMAND.COM.

       When a program infected with the Christmas In Japan Virus is executed,
       the virus will infect zero to one other .COM file in the current
       directory.  If a file is infected, it will increase in length by
       600 bytes, with the virus being located at the end of the infected
       file.

       On December 25, if an infected file is executed, the following message
       will be displayed in the center of the screen:

               "A merry christmas to you"

       The message will flash and will be underlined for approximately half
       the time it is displayed.  If left alone, the message will go away
       after a little while and the program will execute normally, but the
       message will return when another infected .COM file is executed.

       This virus does not appear to do any malicious damage.


 Virus Name:  Christmas Virus
 Aliases:     Tannenbaum, XA1, 1539
 V Status:    Endangered
 Discovery:   March, 1990
 Symptoms:    .COM file growth, display, Partition table destruction
 Origin:      Germany
 Eff Length:  1,539 Bytes
 Type Code:   PNCX - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V61+, VirexPC, VirHunt 2.0+, Pro-Scan 2.01+, NAV,
              IBM Scan 2.00+
 Removal Instructions:  Scan/D, VirHunt 2.0+, Pro-Scan 2.01+, NAV,
              or delete infected files
 General Comments:
       The Christmas Tree, or XA1, Virus was first isolated in March 1990
       by Christoff Fischer of West Germany.  This virus is an encrypting
       virus which will only infect .COM files.

       On April 1st of any year, the Christmas Tree virus will activate,
       destroying the partition table of infected hard disks the first
       time an infected program is executed.  During the period from
       December 24 until January 1st of any year, when an infected
       program is executed, the virus will display a full screen picture
       of a christmas tree.


 Virus Name:  Cookie
 Aliases:
 V Status:    Rare
 Discovery:   January, 1991
 Symptoms:    .COM & .EXE growth; system hangs
 Origin:      Unknown/Europe
 Eff Length:  2,232 bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan, F-Prot, VirexPC, NAV, IBM Scan
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Cookie Virus was received in January, 1991, it is believed to have
       originated in Europe.  This virus is based on the SysLock Virus, though
       it is considerably shorted in length.  Some anti-viral utilities will
       identify this virus as SysLock, though it is listed here separately
       due to its differences in characteristics.  It is a non-resident direct
       action virus which infects .COM and .EXE files, including COMMAND.COM.

       When a program infected with the Cookie Virus is executed, the virus
       will search the current drive and directory for a file to infect.  The
       virus first looks for a .COM file to infect.  If an uninfected .COM
       file is located, it will become infected.  If an uninfected .COM file
       is not found, the virus will then look for an uninfected .EXE file to
       infect.  In other words, all the .COM files in the directory will become
       infected before any of the .EXE files in that directory are infected.
       Infected files will show a file length increase of between 2,232 and
       2,251 bytes in length.  The virus will be located at the end of the
       infected file.  Infected files will not have their date and time in
       the disk directory altered.

       Systems infected with the Cookie Virus may experience system hangs
       when some infected programs are executed.  In some cases, the
       infected program will stop functioning properly after a number of
       executions, though this does not always occur.

       This virus has also been reported to possibly display the message
       "I want a COOKIE!", though the sample received doesn't exhibit this
       behavior.

       Also see: SysLock


 Virus Name:  Crash
 Aliases:     1075
 V Status:    Rumored
 Discovery:   December, 1991
 Symptoms:
 Origin:      USSR
 Eff Length:  1,075 bytes
 Type Code:
 Detection Method: ViruScan V76+
 Removal Instructions:  Delete infected files
 General Comments:
       The Crash or 1075 Virus has had many samples submitted over the last
       few months.  The original samples were from the USSR in December, 1990.
       All submitted samples of this "virus" do not replicate on an XT or 386
       based personal computer.  Instead, the system crashes when the sample
       file is executed.  It may replicate under some other system
       configurations.


 Virus Name:  Crew-2480
 Aliases:     2480
 V Status:    Rare
 Discovery:   February, 1991
 Symptoms:    .COM growth; File date/time changes; System hangs; System reboots
 Origin:      Unknown
 Eff Length:  2,480 bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V76+, IBM Scan 2.00+
 Removal Instructions:  Delete infected files
 General Comments:
       The Crew-2480 Virus was submitted in February, 1991.  Its origin, or
       isolation point is unknown.  This virus is a non-memory resident
       infector of .COM programs over 10K in size.  It will infect COMMAND.COM.

       When a program infected with the Crew-2480 Virus is executed, the virus
       may infect one .COM file over 10K in size.  When COMMAND.COM is infected
       by the virus, the system will reboot.  Infected .COM programs will
       increase in size by 2,480 bytes with the virus being located at the
       end of the infected program.  The file's date and time in the disk
       directory will have been updated to the system date and time when
       infection occurred.

       Besides the symptoms indicated above which occur when files are infected,
       systems with a Crew-2480 infection may also experience system hangs
       when the user attempts to execute infected programs.  Later execution
       of the same program may be successful.  This virus may also display
       a formatted message on some systems in place of the system hang which
       occurs on monochrome systems.


 Virus Name:  Dark Avenger
 Aliases:     Black Avenger, Eddie, Diana, Rabid Avenger
 V Status:    Common
 Discovery:   September, 1989
 Symptoms:    TSR; .COM, .EXE, .SYS file growth; File/Disk Corruption
 Origin:      Bulgaria
 Isolated:    Davis, California, USA
 Eff Length:  1,800 bytes
 Type Code:   PRsAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V36+, F-Prot, IBM Scan, Pro-Scan, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  CleanUp, Pro-Scan 1.4+, F-Prot, VirHunt 2.0+, NAV
 General Comments:
       Dark Avenger was first isolated in the United States at the University
       of California at Davis.  It infects .COM, .EXE, and overlay files,
       including COMMAND.COM.  The virus will install itself into system
       memory, becoming resident, and is extremely prolific at infecting
       any executable files that are openned for any reason.  This includes
       using the DOS COPY and XCOPY commands to copy uninfected files, both
       the source and the target files will end up being infected.  Infected
       files will have their lengths increased by 1,800 bytes.

       The Dark Avenger Virus does perform malicious damage.  The virus
       maintains a counter in the disk's boot sector.  After each sixteenth
       file is infected, the virus will randomly overwrite a sector on the
       disk with a copy of the disk's boot sector.  If the randomly
       selected sector is a portion of a program or data file, the program
       or data file will be corrupted.  Programs and data files which have
       been corrupted by a sector being overwritten are permanently
       damaged and cannot be repaired since the original sector is lost.

       If you are infected with Dark Avenger, shutdown your computer
       and reboot from a Write Protected boot diskette for the system,
       then carefully use a disinfector, following all instructions.
       Be sure to re-scan the system for infection once you have finished
       disinfecting it.

       The Dark Avenger virus contains the words: "The Dark Avenger,
       copyright 1988, 1989", as well as the message: "This program
       was written in the city of Sofia.  Eddie lives.... Somewhere in
       Time!".

       This virus bears no resemblance or similarity to the Jerusalem
       viruses, even though they are similar in size.

       Known variant(s) of Dark Avenger are:
       Dark Avenger-B : Very similar to the Dark Avenger virus, the major
               difference is that .COM files will be reinfected, adding
               1,800 bytes to the file length with each infection.  This
               variant also becomes memory resident in high system memory
               instead of being a low system memory TSR.
               Text strings found in the virus's code include:
                   "Eddie lives...somewhere in time!"
                   "Diana P."
                   "This program was written in the city of Sofia"
                   "(C)1988-1989 Dark Avenger"
       Rabid Avenger  : Rabid Avenger was isolated in the United States in
               April 1991.  This variant of Dark Avenger is based on the
               Dark Avenger-B variant.  Its memory resident portion is located
               at the top of system memory but below the 640K DOS boundary, and
               is 3,696 bytes in length.  Interrupts 21 and 27 are hooked.
               Infected .COM files will increase in length by 1,800 bytes.
               Infected .EXE files will increase in size by 1,806 to 1,823
               bytes.  In both cases, the virus will be located at the end
               of the infected file.  Text strings found in the virus's code
               include:
                   "<- Thanks to the Dark Avenger ->"
                   "Eat us!"
                   "(C) 1991 RABID International Development Corp!"
                   "Scan String Killer Test"
               This variant has also been altered so as to avoid detection by
               anti-viral utilities which are able to detect Dark Avenger.

       Also see: V2000, V1024, V651


 Virus Name:  Datacrime
 Aliases:     1168, Columbus Day
 V Status:    Extinct
 Discovery:   April, 1989
 Symptoms:    .COM file growth, floppy disk access; formats
              hard disk, message any day from Oct 13 to Dec 31.
 Origin:      Holland
 Eff Length:  1,168 bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  AntiCrim, Scan/D/X, Pro-Scan 1.4+, VirexPC, F-Prot,
              VirHunt 2.0+, NAV
 General Comments:
       The Datacrime virus is a parasitic virus, and is also known as
       the 1168 virus.  The Datacrime virus is a non-resident
       virus, infecting .COM files.  The virus was originally
       discovered in Europe shortly after its release in March, 1989.

       The virus will attach itself to the end of a .COM file, increasing
       the file's length by 1168 bytes.  The first 5 bytes of the host
       program are stored off in the virus's code and then replaced by
       a branch instruction so that the virus code will be executed
       before the host program.  In order to propagate, the virus
       searches thru directories for .COM files, other than
       COMMAND.COM and attaches to any found .COM files (except for
       where the 7th letter is a D).  Hard drive partitions are
       searched before the floppy drives are checked.  The virus will
       continue to propagate until the date is after October 12 of any
       year, then when it is executed it will display a message.  The
       decrypted message is something like:

                 "DATACRIME VIRUS"
                 "RELEASED: 1 MARCH 1989".

       Note: only this ASCII message is encrypted in this version.

       A low-level format of the hard disk is then done.

       Errors in the code will make .COM file infection appear random
       and will often make the system crash following infection.

       Unlike the other variants of Datacrime, the original Datacrime
       virus does not replicate, or infect files, until after April 1
       of any year.

       Lastly, if the computer system is using an RLL, SCSI, or PC/AT
       type hard disk controller, all variants of the Datacrime virus
       are not able to successfully format the hard disk, according
       to Jan Terpstra of the Netherlands.

       Also see: Datacrime II, Datacrime IIB, Datacrime-B


 Virus Name:  Datacrime II
 Aliases:     1514, Columbus Day
 V Status:    Endangered
 Discovered:  September, 1989
 Symptoms:    .EXE & .COM file growth, formats disk
 Origin:      Netherlands
 Eff Length:  1,514 bytes
 Type Code:   PNAK - Non-Resident Encrypting .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  AntiCrim, Scan/D/X, Pro-Scan 1.4+, VirexPC, F-Prot,
              VirHunt 2.0+
 General Comments:
       The Datacrime II virus is a variant of the Datacrime virus, the
       major characteristic changes are that the effective length of
       the virus is 1,514 bytes, and that it can now infect both
       .COM and .EXE files, including COMMAND.COM.  There is also an
       encryption mechanism in the Datacrime II virus.

       The Datacrime II virus will not format disks on Mondays.

       Also see: Datacrime, Datacrime IIB, Datacrime-B


 Virus Name:  Datacrime IIB
 Aliases:     1917, Columbus Day
 V Status:    Endangered
 Discovered:  November, 1989
 Symptoms:    .EXE & .COM growth, formats disk, floppy disk access.
 Origin:      Netherlands
 Eff Length:  1,917 bytes
 Type Code:   PNAK - Non-Resident Encrypting .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              VirHunt 2.0+, NAV
 Removal Instructions:  AntiCrim, Scan/D/X, F-Prot, VirexPC, VirHunt 2.0
 General Comments:
       The Datacrime IIB virus is a variant of the Datacrime II virus,
       and was isolated by Jan Terpstra of the Netherlands in
       November, 1989.  This virus, as with Datacrime II, infects
       generic .COM & .EXE files, including COMMAND.COM, adding 1,917
       bytes to the file length.  The virus differs from Datacrime II
       in that the encryption method used by the virus to avoid
       detection has been changed.

       The Datacrime IIB virus will not format disks on Mondays.

       Also see: Datacrime, Datacrime II, Datacrime-B


 Virus Name:  Datacrime-B
 Aliases:     1280, Columbus Day
 V Status:    Extinct
 Discovered:  April, 1989
 Symptoms:    .EXE file growth, formats MFM/RLL hard drives, odd
              floppy disk access.
 Origin:      Netherlands
 Eff Length:  1,280 bytes
 Type Code:   PNE - Parasitic Non-Resident Generic .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: AntiCrim, Scan/D/X, VirexPC, Pro-Scan 1.4+, F-Prot,
              VirHunt 2.0, NAV
 General Comments:
       The Datacrime-B virus is a variant of the Datacrime virus, the
       differences being that the effective length of the virus is
       1,280 bytes, and instead of infecting .COM files, .EXE files
       are infected.

       Also see: Datacrime, Datacrime II, Datacrime II-B


 Virus Name:  DataLock
 Aliases:     DataLock 1.00, V920
 V Status:    Common
 Discovered:  November, 1990
 Symptoms:    .EXE & COMMAND.COM file growth; decrease in system and available
              memory; file date/time changes
 Origin:      USA
 Eff Length:  920 bytes
 Type Code:   PRtEK - Parasitic Resident .EXE and COMMAND.COM Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Clean-Up V71+, or Delete infected files
 General Comments:
       The DataLock, or V920, Virus was isolated in many locations in the
       United States starting on November 1, 1990.  This virus is a generic
       memory resident infector of .EXE files, but it will also infect
       COMMAND.COM if it is executed.

       The first time a program infected with the DataLock Virus is executed,
       the virus will install itself memory resident at the top of free memory,
       but below the 640K DOS boundary.  Infected systems will find that total
       system memory and available free memory will be 2,048 bytes less than
       is expected.  Interrupt 21 will be hooked by the virus.

       After the virus is memory resident, any .EXE file that is executed will
       be infected by the virus.  Infected files will have a file length
       increase of 920 bytes, and their date/time indicated in the disk
       directory will have been changed to the system date and time when the
       infection occurred.  The virus is located at the end of infected files.
       The following text, indicating the virus's name, can be found at the
       end of all infected files:

               "DataLock version 1.00"

       It is unknown if DataLock carries an activation date, or its potential
       for damage.


 Virus Name:  dBASE
 Aliases:     DBF Virus
 V Status:    Extinct
 Discovered:  September, 1988
 Symptoms:    .COM & .OVL file growth, corrupt .DBF files, TSR, FAT and root
              directory overwritten
 Origin:      New York, USA
 Eff Length:  1,864 bytes
 Type Code:   PRC - Parasitic Resident .COM and Overlay Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, Pro-Scan 1.4+, F-Prot, VirHunt 2.0+, NAV
 General Comments:
       The dBASE virus was discovered by Ross Greenberg of New York.
       This virus infects .COM & .OVL files, and will corrupt data in
       .DBF files by randomly transposing bytes in any open .DBF file.
       It keeps track of which files and bytes were transposed in a
       hidden file (BUG.DAT) in the same directory as the .DBF file(s).
       The virus restores these bytes if the file is read, so it
       appears that nothing is wrong.  Once the BUG.DAT file is 90
       days old or more, the virus will overwrite the FAT and root
       directory on the disk.

       After this virus has been detected, if you remove the infected
       dBASE program and replace it with a clean copy, your DBF files
       that were openned during the period that you were infected
       will be useless since they are garbled on the disk even
       though they would be displayed as expected by the infected
       dBASE program.


 Virus Name:  Deicide
 Aliases:     Glenn
 V Status:    Rare
 Discovered:  February, 1991
 Symptoms:    .COM files overwritten; Message; FAT Corruption; System hang
 Origin:      Netherlands
 Eff Length:  666 Bytes
 Type Code:   ONC - Overwriting Non-Resident .COM Infector
 Detection Method:
 Removal Instructions: Delete Infected Programs
 General Comments:
       The Deicide Virus was received in February, 1991 from the Netherlands.
       This virus is a non-resident overwriting virus which infects .COM files,
       but not COMMAND.COM.

       When a program infected with Deicide is executed, the virus will
       search the current directory for an uninfected .COM program.  If an
       uninfected .COM program is found, the virus will infect it, overwriting
       the first 666 bytes of the program with the virus.  If the newly
       infected program's original file length was 666 bytes or more, then no
       file length change will show in the disk directory.  If originally the
       program was smaller than 666 bytes, its length will now be 666 bytes.
       The following message may be displayed by the virus after infecting
       a file:

               "File corruption error."

       If the virus does not find an uninfected .COM program in the current
       directory, it will display the following message double spaced, and
       overwrite the first 80 sectors of the system hard disk:

               "DEICIDE!
                Glenn (666) says : BYE BYE HARDDISK!!
                Next time be carufull with illegal stuff"

       The above messages can be found in all infected files, along with the
       following message which is not displayed:

                "This experimental virus was written by Glenn Benton
                 to see if I can make a virus while learning machinecode
                 for 2,5 months. (C) 10-23-1990 by Glenn.
                 I keep on going making virusses."


 Virus Name:  Den Zuk
 Aliases:     Search, Venezuelan
 V Status:    Common
 Discovered:  September, 1988
 Symptoms:    Message, floppy format, TSR, BSC
 Origin:      Indonesia
 Eff Length:  N/A
 Type Code:   RtF - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions: MDisk, CleanUp, F-Prot, Pro-Scan 1.4+, NAV,
              or DOS SYS command
 General Comments:
       The Den Zuk virus is a memory-resident, boot sector infector of
       360K 5 1/4" diskettes.  The virus can infect any diskette
       in a floppy drive that is accessed, even if the diskette is
       not bootable.  If an attempt is made to boot the system with an
       infected non-system disk, Den Zuk will install itself into
       memory even though the boot failed.  After the system is booted
       with an infected diskette, a purple "DEN ZUK" graphic will appear
       after a CTL-ALT-DEL is performed if the system has a CGA, EGA, or
       VGA monitor.  While the original Den Zuk virus did not cause any
       damage to the system, some variants maintain a counter of how
       many times the system has been rebooted, and after the counter
       reaches its limit, the floppy in the disk drive is reformatted.
       The counter in these variants of the virus is usually in the
       range of 5 to 10.

       The following text strings can be found in the viral code on
       diskettes which have been infected with the Den Zuk virus:

                 "Welcome to the
                     C l u b
                  --The HackerS--
                      Hackin'
                   All The Time

                   The HackerS"

       The diskette volume label of infected diskettes may be changed
       to Y.C.1.E.R.P., though this change only occurs if the Den Zuk
       virus removed a Pakistani Brain infection before infecting the
       diskette with Den Zuk.  The Den Zuk virus will also remove
       an Ohio virus infection before infecting the diskette with
       Den Zuk.

       The Den Zuk virus is thought to be written by the same person
       or persons as the Ohio virus.  The "Y.C.1.E.R.P." string is
       found in the Ohio virus, and the viral code is similar in
       many respects.

       Also see: Ohio


 Virus Name:  Destructor V4.00
 Aliases:     Destructor
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM & .EXE growth; decrease in system and available free memory
 Origin:      Bulgaria
 Eff Length:  1,150 Bytes
 Type Code:   PRtAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Destructor V4.00 Virus was received in December, 1990.  This virus
       is from Bulgaria, and is a memory resident infector of .COM and .EXE
       files, including COMMAND.COM.

       When the first program infected with the Destructor V4.00 Virus is
       executed, the virus will install itself memory resident at the top of
       system memory but below the 640K DOS boundary.  Interrupt 12's return
       is moved.  Total system memory and available free memory will be
       1,216 bytes less than what is expected on the infected system.  At this
       time, the virus will also infect COMMAND.COM if it is not already
       infected.

       Once Destructor V4.00 is memory resident, it will infect programs as
       they are openned or executed.
       Infected .COM programs will have increased in size by 1,150 bytes.
       .EXE programs will have increased in size by 1,154 to 1,162 bytes.
       In both cases, the virus will be located at the end of the infected
       file.  This virus does not alter the file's date/time in the disk
       directory, and it also makes no attempt to hide the file length increase
       on infected programs.

       The following text string can be found in files infected with this
       virus:

               "DESTRUCTOR  V4.00  (c) 1990 by ATA

       It is unknown what Destructor V4.00 does, if anything, besides
       replicate.


 Virus Name:  Devil's Dance
 Aliases:     Mexican
 V Status:    Rare
 Discovered:  December, 1989
 Symptoms:    Message, .COM growth, FAT corruption, TSR
 Origin:      Mexico
 Eff Length:  941 Bytes
 Type Code:   PRCT - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V52+, IBM Scan, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions: Scan/D, Pro-Scan 1.4+, VirHunt 2.0+, NAV,
              or delete infected files
 General Comments:
       The Devil's Dance virus was first isolated in December, 1989,
       by Mao Fragoso of Mexico City.  The Devil's Dance virus
       increases the size of infected .COM files by 941 bytes, and
       will infect a file multiple times until the file becomes too
       large to fit in available system memory.

       Once an infected program has been run, any subsequent warm-
       reboot (CTL-ALT-DEL) will result in the following message
       being displayed:

       "DID YOU EVER DANCE WITH THE DEVIL IN THE WEAK MOONLIGHT?
                            PRAY FOR YOUR DISKS!!
                                The Joker"

       The Devil's Dance virus is destructive.  After the first 2,000
       keystrokes, the virus starts changing the colors of any text
       displayed on the system monitor.  After the first 5,000
       keystrokes, the virus erases the first copy of the FAT.  At
       this point, when the system is rebooted, it will display the
       message above and again destroy the first copy of the FAT, then
       allow the boot to proceed.


 Virus Name:  Dir Virus
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; TSR; Sluggishness of DIR commands;
              File allocation errors
 Origin:      USSR
 Eff Length:  691 Bytes
 Type Code:   PRsCK - Parasitic Resident .COM  Infector
 Detection Method:  ViruScan V74+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Dir Virus was submitted in January, 1991.  It originated in the
       USSR.  The Dir Virus is a memory resident infector of .COM programs,
       including COMMAND.COM.

       The first time a program infected with the Dir Virus is executed, the
       virus will install itself memory resident as a low system memory TSR
       of 1,008 bytes.  Interrupt 21 will be hooked by the virus.  If
       COMMAND.COM is not already infected, it will become infected at this
       time.

       After the Dir Virus is memory resident, it will only infect .COM
       programs when a DOS Dir command is performed.  It does not infect
       programs on execution, or when .COM files are openned.  When a Dir
       command is performed, the first uninfected .COM program that is found
       in the directory will become infected.  When the virus infects a .COM
       file, there will be a pause in the output of the dir command while the
       program is being infected, then the output will continue.

       Infected programs will increase in size by 691 bytes, though the file
       length increase cannot be seen when a directory command is performed if
       the virus is memory resident.  The virus will be located at the end of
       infected programs.  Infected programs will not have their date and time
       altered by the virus.

       Systems infected with the Dir Virus will receive file allocation errors
       when the DOS ChkDsk program is executed on a drive containing infected
       programs.  If the virus is not memory resident, these errors will not
       be found.  Execution of the DOS ChkDsk program with the /F option when
       the virus is memory resident will result in corruption of the infected
       programs.

       This virus does not appear to contain any activation mechanism.


 Virus Name:  Discom
 Aliases:
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    TSR; .COM & .EXE growth
 Origin:      Unknown
 Eff Length:  2,053 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method: ViruScan V76+, IBM Scan 2.00+
 Removal Instructions: CleanUp V75+, or Delete infected files
 General Comments:
       The Discom Virus was submitted in November, 1990.  The location where
       the sample was isolated is unknown.  Discom is a memory resident
       infector of .COM and .EXE files, and will not infect COMMAND.COM.

       This virus is based on the Jerusalem Virus, and also contains some code
       from the Sunday Virus.  As such, some anti-viral utilities may identify
       files infected with this virus as containing both Jerusalem and Sunday.
       This virus does not exhibit symptoms or the activation of either the
       Jerusalem or Sunday viruses.

       The first time a program infected with the Discom Virus is executed,
       the virus will install itself memory resident as a 2,304 byte low
       system memory TSR.  Interrupts 08 and 21 will be hooked by the virus.

       Once memory resident, the virus will infect .COM and .EXE files when
       they are executed.  Infected .COM files will increase in length by
       2,053 bytes and have the virus located at the beginning of the infected
       file.  Infected .EXE files will increase in length by 2,059 to 2,068
       bytes with the virus being located at the end of the file.  All infected
       files will end with the following hex character string: 11121704D0.

       Unlike many Jerusalem Variants, this virus does not exhibit a system
       slowdown after being memory resident for 30 minutes, and no "black
       window" appears.


 Virus Name:  Disk Killer
 Aliases:     Computer Ogre, Disk Ogre, Ogre
 V Status:    Common
 Discovered:  April, 1989
 Symptoms:    Bad blocks, message, BSC, TSR, encryption of disk
 Origin:      Taiwan
 Isolated:    Milpitas, California, USA
 Eff Length:  N/A
 Type Code:   BRtT - Resident Boot Sector Infector
 Detection Method:  ViruScan V39+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  MDisk, CleanUp, Pro-Scan 1.4+, F-Prot, NAV, or
              DOS COPY & SYS
 General Comments:
       The Disk Killer virus is a boot sector infector that spreads by
       writing copies of itself to 3 blocks on either a floppy or
       hard disk.  The virus does not care if these blocks are in use
       by another program or are part of a file.  These blocks will then
       be marked as bad in the FAT so that they cannot be overwritten.
       The boot sector is patched so that when the system is booted, the
       virus code will be executed and it can attempt to infect any new
       disks exposed to the system.

       The virus keeps track of the elapsed disk usage time since initial
       infection, and does no harm until it has reached a predetermined
       limit.  The predetermined limit is approximately 48 hours.  (On
       most systems, Disk Killer will reach its limit within 1 - 6
       weeks of its initial hard disk infection.)

       When the limit is reached or exceeded and the system is rebooted,
       a message is displayed identifying COMPUTER OGRE and a date of
       April 1.  It then says to leave alone and proceeds to encrypt the
       disk by alternately XORing sectors with 0AAAAh and 05555h,
       effectively destroying the information on the disk.  The only recourse
       after Disk Killer has activated and encrypted the entire disk is to
       reformat.

       The message text that is displayed upon activation, and can be found
       in the viral code is:

         "Disk Killer -- Version 1.00 by COMPUTER OGRE 04/01/89

                                Warning!!

          Don't turn off the power or remove the diskette while Disk Killer is
          Processing!

                                PROCESSING

          Now you can turn off the power.  I wish you Luck!"

       It is important to note that when the message is displayed, if the
       system is turned off immediately it may be possible to salvage
       some files on the disk using various utility programs as this
       virus first destroys the boot, FAT, and directory blocks.

       Disk Killer can be removed by using McAfee Associate's MDisk or
       CleanUp utility, or the DOS SYS command, to overwrite the boot
       sector on hard disks or bootable floppies.  On non-system floppies,
       files can be copied to non-infected floppies, followed by reformatting
       the infected floppies.  Be sure to reboot the system from a
       write protected master diskette before attempting to remove the
       virus first or you will be reinfected by the virus in memory.

       Note: Disk Killer may have damaged one or more files on the disk
       when it wrote a portion of its viral code to 3 blocks on the disk.
       Once the boot sector has been disinfected as indicated above, these
       corrupted files cannot reinfect the system, however they should be
       replaced with backup copies since the 3 blocks were overwritten.

       Note: Do not use the DOS DiskCopy program to backup infected
       diskettes as the new backup diskettes will contain the virus
       as well.


 Virus Name:  Do-Nothing Virus
 Aliases:     The Stupid Virus
 V Status:    Extinct
 Discovered:  October, 1989
 Symptoms:    .COM file growth, TSR (see text)
 Origin:      Israel
 Eff Length:  608 Bytes
 Type Code:   PRfC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, Pro-Scan, VirexPC, AVTK 3.5+,
              NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D/X, Pro-Scan 1.4+, F-Prot, or NAV
 General Comments:
       This virus was first reported by Yuval Tal of Israel in
       October, 1989.  The virus will infect .COM files, but only the
       first one in the current directory, whether it was previously
       infected or not.  The Do-Nothing virus is also memory
       resident, always installing itself to memory address
       9800:100h, and can only infect systems with 640K of memory.
       The virus does not protect this area of memory in any way,
       and other programs which use this area will overwrite it in
       memory, removing the program from being memory resident.

       The Do-Nothing virus does no apparent damage, nor does it
       affect operation of the system in any observable way, thus
       its name.

       Also see: Saddam


 Virus Name:  Doom II-B
 Aliases:
 V Status:    New
 Discovered:  May, 1991
 Symptoms:    .COM & .EXE growth; Possible system hang on screen writes
 Origin:      USA
 Eff Length:  1,252 Bytes
 Type Code:   PRbAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan V77+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Doom II-B Virus was submitted in May, 1991 by the PCVRF in the
       United States.  This virus is actually a reengineered variant of the
       Doom II Virus from Taiwan.  (Doom II has not been included in this
       listing as received samples do not replicate.)  Doom II-B is a memory
       resident infector of .COM and .EXE programs.

       The first time a program infected with Doom II-B is executed, Doom II-B
       will install itself memory resident in memory located on the system's
       video card, along with a hook to this memory in low system memory.
       Interrupts 1C, 21, 24, and 98 will be hooked by the virus.  Infected
       systems will not have any change in total system or available free
       memory.

       Once memory resident, Doom II-B will infect .COM and .EXE programs,
       including COMMAND.COM, when they are executed.  Infected .COM and .EXE
       files increase in size by 1,252 bytes with the virus being located at
       the end of the infected file.  The virus does not hide the file length
       increase, nor is the file date and time in the disk directory altered.

       Systems infected with Doom II-B may experience system hangs when
       programs attempt to write to the system display.  These hangs occur
       due to the virus being resident in the video card memory, thus making
       it unavailable.  When these hangs occur, typically the monitor display
       will be blanked and the system keyboard will be locked out.

       It is unknown if Doom II-B does anything besides replicate.


 Virus Name:  Dot Killer
 Aliases:     944, Point Killer
 V Status:    Rare
 Discovered:  October, 1990
 Symptoms:    .COM growth; removal of all dots (.) from display
 Origin:      Koszalin, Poland
 Eff Length:  944
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V72+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Dot Killer Virus was isolated in Koszalin, Poland in October, 1990.
       It is a non-resident infector of .COM files, including COMMAND.COM.

       When a program infected with the Dot Killer Virus is executed, the
       virus will infect one other .COM file in the current directory.
       Infected .COM files will increase in length by 944 bytes.  The virus
       will be located at the end of infected files.

       While the Dot Killer Virus contains code to attempt to avoid infecting
       the program pointed to by the COMSPEC environmental parameter, this
       logic contains a bug and does not function properly.  If COMMAND.COM,
       or the program pointed to by COMSPEC, is located in the current
       directory it will become infected just like any other .COM program.

       When the Dot Killer Virus activates, it will remove all dots (.) from
       the system display.


 Virus Name:  Dutch 555
 Aliases:     555
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    .COM & .EXE growth; Decrease in system and available memory
 Origin:      Netherlands
 Eff Length:  555 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V75+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, CleanUp V77+ or Delete Infected Files
 General Comments:
       The Dutch 555 Virus was received in February 1991 from Righard
       Zwienenberg of the Netherlands.  This virus was accidently released
       into the public domain by its author in November, 1990.  It is a
       memory resident infector of .COM and .EXE files, including COMMAND.COM.

       The first time a program infected with the Dutch 555 Virus is executed,
       the virus will install itself memory resident at the top of system
       memory, but below the 640K DOS boundary.  The interrupt 12 return is
       not moved, though the DOS ChkDsk program will show a decrease in total
       system and available free memory of 560 bytes.  Interrupt 21 will be
       hooked by the virus.

       Once the Dutch 555 Virus is memory resident, it will infect .COM and
       .EXE files, including COMMAND.COM, as they are executed.  Infected files
       will increase in size by 555 bytes, with the virus being located at the
       end of the infected file.

       This virus does not do anything besides replicate.


 Virus Name:  EDV
 Aliases:     Cursy, Stealth Virus
 V Status:    Rare
 Discovered:  1988
 Symptoms:    BSC; partition table corruption; unusual system crashes
 Origin:      France
 Eff Length:  N/A
 Type Code:   BRX - Resident Boot Sector/Partition Table Infector
 Detection Method:  ViruScan V58+, IBM Scan, Pro-Scan 1.4+, VirHunt 2.0+, NAV
 Removal Instructions:  MDisk/P, CleanUp V67+, Pro-Scan 1.4+, or NAV
 General Comments:
       The EDV, or Cursy, Virus was first discovered in Le Havre, France in
       1988 by Jean-Luc Nail.  At that time, it was named the Cursy Virus.
       Later, in January 1990, it was isolated separately and named the
       EDV virus.  This virus is a memory resident infector of floppy
       diskette boot sectors and hard disk partition tables.

       When a system is booted from a diskette infected with the EDV virus,
       the virus will install itself memory resident at the top of high
       system memory.  The value returned by interrupt 12 will be decreased.

       Once the virus is memory resident, and disk accessed by the system
       will become infected.  When the virus infects a diskette, it moves
       the original boot sector to side 1, track 39, sector 8.  After
       moving the original boot sector, it then copies the virus's code
       to absolute sector 0, the boot sector of the diskette.

       EDV will also infect hard disk drives when they are accessed.  In the
       case of hard disks, the virus will move absolute sector 0 (the
       partition table) to side 1, track 39, sector 8 as though it were a
       360K 5.25" floppy diskette.  After moving the partition table, it will
       then overwrite the partition table with the viral code.

       Once the virus has infected six disks with the virus in memory, the
       EDV virus will activate.  Upon activation, the virus access the
       keyboard interrupt to disable the keyboard and then will overwrite
       the first 3 tracks of each disk on the system, starting with the
       hard disks.  After overwriting the disks, it will then display the
       following message:

               "That rings a bell, no? From Cursy"

       Upon activation, the user must power off the machine and reboot from
       a system diskette in order to regain any control over the machine.

       The following identification string appears at the very end of the
       boot sector on infected floppy disks and the partition table of
       infected hard drives, though it cannot be seen if the virus is
       in memory:

            "MSDOS Vers. E.D.V."

       Jean-Luc Nail has indicated that the EDV or Cursy virus is quiet
       common in the Le Havre area of France, although it is rare outside
       of France.


 Virus Name:  Eight Tunes
 Aliases:     1971
 V Status:    Rare
 Discovered:  April, 1990
 Symptoms:    file growth, music, decrease in available memory
 Origin:      West Germany
 Eff Length:  1,971 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V62+, Pro-Scan 1.4+, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, VirHunt 2.0+, NAV, or delete infected files
 General Comments:
       The Eight Tunes, or 1971, Virus was originally isolated in April
       1990 by Fridrik Skulason of Iceland.  This virus is a memory resident
       generic file infector of .COM, .EXE, and overlay files.  The virus will
       not infect COMMAND.COM, or .COM files which are smaller than 8K.
       After the virus is memory resident, programs are infected as they
       are executed.  Infected files will increase in length by between
       1,971 - 1,985 bytes.

       Available memory will decrease by 1,984 bytes when the virus is
       present.

       This virus does not cause system damage, however it is disruptive.
       When the virus is memory resident, it will play 8 German folk songs
       at random intervals thirty minutes after the virus becomes memory
       resident.


 Virus Name:  Enigma
 Aliases:     Cracker Jack
 V Status:    Rare
 Discovered:  February, 1991
 Symptoms:    .EXE growth
 Origin:      Italy
 Eff Length:  1,755 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method: ViruScan V76+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Enigma Virus was submitted in February, 1991, by Alberto Colusa of
       Italy.  This virus is a non-resident infector of .EXE files.  The
       original submitted sample of this virus was not a natural infection of
       the virus, being on a .COM file, so the virus may actually be a
       research virus.

       When a program infected with Enigma is executed, one .EXE program in
       the current directory will be infected by the virus.  Infected .EXE
       programs will increase in length by 1,755 bytes.  The virus will be
       located at the end of infected programs.  Infected programs will also
       contain the following text strings:

               "This is the voice of the Enigma virus......
                the spirits of the hell are coming back!"
               "(C) 1991 by Cracker Jack * Italy * *.exe"
               "newenigmavir"

       It is not known if Enigma does anything besides replicate.

       Also see: Yankee 2


 Virus Name:  Evil
 Aliases:     P1, V1701New
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    .COM growth, system reboots, CHKDSK program failure,
              COMMAND.COM header change
 Origin:      Bulgaria
 Eff Length:  1,701 Bytes
 Type Code:   PRhCK - Parasitic Resident .COM Infector
 Detection Method: ViruScan V66+, NAV
 Removal Instructions: Scan/D, NAV, or delete infected files
 General Comments:
       The Evil Virus is of Bulgarian origin, and was submitted to
       the author of this document in July, 1990 by Vesselin Bontchev.
       This virus is one of a family of three (3) viruses which may be
       referred to as the P1 or Phoenix Family.  Each of these viruses is
       being documented separately due to their varying characteristics.
       The Evil virus is a memory resident, generic infector of .COM
       files, and will infect COMMAND.COM.  It is the most advanced of the
       three viruses in the Phoenix Family.

       The Evil, or V1701New, Virus is a later version of the PhoenixD virus.

       The first time a program infected with the Evil virus is executed,
       the virus will install itself memory resident in free high memory,
       reserving 8,192 bytes.  Interrupt 2A will be hooked by the virus.
       System total memory and free memory will decrease by 8,192 bytes.
       Evil will then check to see if the current drive's root directory
       contains a copy of COMMAND.COM.  If a copy of COMMAND.COM is found,
       it will be infected by Evil by overwriting part of the binary zero
       portion of the program, and changing the program's header information.
       COMMAND.COM will not change in file length.  The virus will then
       similarly infect COMMAND.COM residing in the C: drive root directory.

       After becoming memory resident, the virus will attempt to infect any
       .COM file executed.  Evil is a better replicator than either the
       original Phoenix Virus or PhoenixD, and was successful in infecting
       .COM files in all cases on the author's system.  Infected files will
       increase in size by 1,701 bytes.

       Evil is not able to recognize when it has previously infected a
       file, so it may reinfect .COM files several times.  Each infection will
       result in another 1,701 bytes of viral code being appended to the
       file.

       Like PhoenixD, Evil will infect files when they are openned for
       any reason in addition to when they are executed.  The simple act of
       copying a .COM file will result in both the source and target .COM
       files being infected.

       Systems infected with the Evil virus will experience problems with
       executing CHKDSK.COM.  Attempts to execute this program with Evil
       memory resident will result in a warm reboot of the system occurring.
       The system, however, will not perform either a RAM memory check or
       request Date and Time if an autoexec.bat file is not present.

       This virus is not related to the Cascade (1701/1704) virus.

       The Evil Virus employs a complex encryption mechanism, and virus
       scanners which are only able to look for simple hex strings will not
       be able to detect it.  There is no simple hex string in this virus
       that is common to all infected samples.

       Known variant(s) of Evil are:
       Evil-B : This is a earlier version of Evil, and is a rather
                poor replicator.  It also has not to viable as infected
                programs will hang when they are executed, with the
                exception of the Runme.Exe file which the author
                received.  The Runme.Exe file was probably the original
                release file distributed by the virus's author.
                (Originally listed in VSUM9008 as V1701New-B)

       Also see: Phoenix, PhoenixD


 Virus Name:  Evil Empire
 Aliases:     Evil Empire-A
 V Status:    New
 Discovered:  April, 1991
 Symptoms:    BSR; Decrease in total system and available free memory
 Origin:      Alberta, Canada
 Eff Length:  N/A
 Type Code:   BRtX - Resident Boot Sector/Partition Table Infector
 Detection Method:  ViruScan V77+
 Removal Instructions: M-Disk/P
 General Comments:
       The Evil Empire Virus was isolated in Alberta, Canada, in April 1991.
       This virus is a memory resident infector of floppy boot sectors and the
       hard disk partition table.  It is based on the Stoned Virus.

       The first time a system is booted from a diskette infected with the
       Evil Empire Virus, this virus will install itself memory resident as
       well as infect the hard disk partition table.  The virus will be
       resident at the top of system memory, but below the 640K DOS boundary,
       and interrupt 12's return will be moved.  Total system and available
       free memory will be 2,048 bytes less than expected.  The hard disk's
       partition table will be infected, with the virus having moved the
       original partition table to cylinder 0, side 0, sector 6, and then
       writing a copy of itself to cylinder 0, side 0, sector 0 (the partition
       table location).

       After Evil Empire is memory resident, it will infect diskettes non-
       write protected diskettes as they are accessed on the system.  Infected
       diskettes will have their original boot sector moved to sector 10,
       which is part of the root directory.

       The text string "PC<heart>AT", with <heart> being an ASCII heart
       character, can be found near the end of the floppy boot sector as well
       as in the hard disk partition table of infected systems.

       Diskettes may be damaged when they are infected with Evil Empire due
       to the virus overwriting sector 10 of the disk directory.  If root
       directory entries were originally in this sector, they will be lost.

       A note on disinfecting Evil Empire: copying the original partition
       table from sector 6 to sector 0 will result in the diskette being
       disinfected, but it will also now be a non-system hard disk.  If this
       occurs, Norton Disk Doctor can be used to correct the situation.

       Some anti-viral programs may detect Evil Empire as Azusa.

       Also see: Azusa, Evil Empire-B, Stoned


 Virus Name:  Evil Empire-B
 Aliases:     Empire
 V Status:    New
 Discovered:  April, 1991
 Symptoms:    BSR; Decrease in total system and available free memory
 Origin:      Alberta, Canada
 Eff Length:  N/A
 Type Code:   BRtX - Resident Boot Sector/Partition Table Infector
 Detection Method:  ViruScan V77+
 Removal Instructions: M-Disk/P
 General Comments:
       The Evil Empire-B Virus was isolated in Alberta, Canada, in April 1991.
       It is a memory resident infector of diskette boot sectors as well as
       the hard disk partition table.  This virus is based on the Evil Empire
       Virus listed above, and may be identified by some anti-viral programs
       as Empire.

       The first time a system is booted from a diskette infected with Evil
       Empire-B, the virus will install itself memory resident as well as
       infect the hard disk partition table.  In memory, the virus will be
       located at the top of system memory, but below the 640K DOS boundary.
       Interrupt 12's return will be moved.  Total system and available free
       memory will decrease by 1,024 bytes.  When the virus infects the hard
       disk partition table, it will copy the original partition table to
       cylinder 0, side 0, sector 3, and then replace the original partition
       table at sector 0 with a copy of itself.  This copy will extend to
       sector 1 as the virus is longer than 512 bytes.

       After Evil Empire-B is memory resident, it will infect non-write
       protected diskettes which are accessed on the system.  On diskettes,
       the virus copies the original boot sector to sector 11, which is a
       part of the root directory.  It then writes a copy of itself to sector
       0, boot sector location.  Note that if the disk directory originally
       contained entries in sector 11, those entries will be lost, resulting
       in the files disappearing from the disk directory.

       Evil Empire-B is a fully encrypted virus, no text messages will appear
       in infected boot sectors or partition tables.  The following message,
       however, may be displayed on boot of systems (note: replace <heart> with
       the ASCII heart character):

           "<heart>PC<heart>AT LIVE F<heart>R L<heart>VE <heart><heart>"

       Evil Empire-B can be disinfected after powering off the system and
       booting from a clean DOS diskette.  The original partition table on
       the hard disk should then be copied back to absolute sector 0.
       Alternately, M-Disk can be used to remove the infection by using the
       M-Disk /P option.

       Also see: Evil Empire, Stoned


 Virus Name:  F-Word Virus
 Aliases:     Fuck You
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM growth; decrease in system and available free memory;
              file date/time changes
 Origin:      USSR
 Eff Length:  417 Bytes
 Type Code:   PRtCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The F-Word, or Fuck You, Virus was submitted in December, 1990 and
       is from the USSR.  This virus is a memory resident infector of COM
       files, including COMMAND.COM.

       The first time a program infected with the F-Word Virus is executed
       the virus will install itself memory resident at the top of system
       memory but below the 640K DOS boundary.  Interrupt 12's return will
       be moved.  Total system memory and available free memory will decrease
       by 1,024 bytes.  Interrupts 08 and 21 will be hooked by the virus.

       After F-Word is memory resident, it will infect COM files over
       approximately 2K in length when they are executed.  Infected files will
       have a length increase of 417 bytes with the virus being located at the
       end of the program.  The file's date and time in the directory will also
       have been changed to the system date and time when infection occurred.

       Attempts to executed the DOS Edlin program will result in a
       "Invalid drive of file name" message being displayed, and the program
       terminated.

       The text string "Fuck You!" can be found in all infected files.


 Virus Name:  Father Christmas
 Aliases:     Choinka
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    .COM growth; lost cluster; cross-linking of files;
              graphic and message displayed on activation
 Origin:      Poland
 Eff Length:  1,881 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V71+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The Father Christmas, or Choinka, Virus was discovered in Poland in
       November, 1990.  This virus is based on the Vienna Virus, and is a
       non-resident infector of .COM files, including COMMAND.COM.

       When a program infected with the Father Christmas Virus is executed,
       the virus will infect one other .COM file in the current directory.
       If no uninfected .COM files exist in the current directory, the virus
       will follow the system path to find an uninfected program.  Infected
       files will increase in length by 1,881 bytes with the virus being
       located at the end of the infected program.

       Systems infected with the Father Christmas Virus may notice crosslinking
       of files and lost clusters.

       During the period from December 19 - December 31 of any year, this
       virus will activate.  On these dates, when infected programs are
       executed a christmas trees graphic is displayed on the system monitor
       with the following message:

                    Merry Christmas
                           &
                   a  Happy New Year
               for all my lovely friends
                         from
                    FATHER CHRISTMAS

       If the graphic is displayed, the user must strike a key in order to
       have the program being executed finish running.


 Virus Name:  Fellowship
 Aliases:     1022
 V Status:    Rare
 Discovered:  July, 1990
 Isolated:    Australia
 Symptoms:    TSR, .COM & .EXE file growth
 Origin:      Malaysia
 Eff Length:  1,022 Bytes
 Type Code:   PRsE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan V66+, F-Prot 1.12+, Pro-Scan 2.01+, NAV,
              IBM Scan 2.00+
 Removal Instructions: CleanUp V77+, F-Prot 1.12+, NAV,
              or Delete infected files
 General Comments:
       The Fellowship or 1022 Virus was isolated in Australia in July 1990.
       Fellowship is a memory resident generic infector of .EXE files.  It
       does not infect .COM or overlay files.

       The first time a program infected with the Fellowship Virus is
       executed, the virus will install itself memory resident as a 2,048
       byte TSR in low system memory.  Available free memory will be decreased
       by a corresponding 2,048 bytes.  Interrupt 21 will also now be
       controlled by the virus.

       After the virus is memory resident, the virus will infect .EXE files
       when they are executed.  Infected .EXE files will increase in size
       by between 1,019 and 1,027 bytes.  The virus's code will be located
       at the end of infected files.

       Infected files will contain the following text strings very close to
       the end of the file:

             "This message is dedicated to
              all fellow PC users on Earth
              Toward A Better Tomorrow
              And a better Place To Live In"

             "03/03/90 KV KL MAL"

       This virus is believed to have originated in Kuala Lumpur, Malaysia.


 Virus Name:  Fish Virus
 Aliases:     European Fish Viruses, Fish 6, Stealth Virus
 V Status:    Rare
 Discovered:  May 1990
 Symptoms:    .COM & .EXE growth, monitor/display flickering, system
              memory decrease
 Origin:      West Germany
 Eff Length:  3,584  Bytes
 Type Code:   PRsAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V63+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, CleanUp V66+, Pro-Scan 1.4+, VirHunt 2.0+,
              NAV, or delete infected files
 General Comments:
       The Fish Virus was isolated in May 1990.  At the time of isolation,
       it was reported to be widespread in Europe, and it is thought to
       have originated in West Germany.  It is a generic resident .COM
       and .EXE infector, and will infect COMMAND.COM.  This virus will
       remain memory resident thru a warm reboot, or Ctrl-Alt-Del.  The
       virus is encrypted, though infected programs can be found by
       searching for the text string "FISH FI" appearing near the end of
       the program.  The "FISH FI" string may later disappear from the
       program.

       The first time a program infected with the Fish Virus is executed,
       the virus will go memory resident, installing itself into the low
       available free memory.  If interrupt 13 has not been hooked by
       another program, it will hook interrupt 13.  If it can hook
       interrupt 13, it will take up 8,192 bytes in memory.  If the virus
       cannot hook interrupt 13 because another program is already using it,
       it will be 4,096 bytes in memory.

       When interrupt 13 is not hooked, and the virus is memory resident,
       the virus will cause a random warm reboot, thus allowing it to
       infect COMMAND.COM and hook interrupt 13.  Warm reboots do not
       appear to randomly occur after interrupt 13 has been hooked.

       After the virus is memory resident, all .COM and .EXE programs which
       are openned for any reason will be infected.  Infected programs
       increase in length by 3,584 bytes.  The increase in program size
       cannot be seen by listing the disk directory if the virus is in
       memory.  Also, if a CHKDSK command is run on an infected system,
       it will detect file allocation errors on infected files.  If CHKDSK
       is run with the /F option, it will result in lost clusters and
       cross-linking of files.

       The virus slows down video writes, and flickering of the monitor
       display can be noticed on an infected system.

       Anti-viral programs which perform CRC checking cannot detect the
       infection of the program by the Fish Virus if the virus is memory
       resident.  This virus can also bypass software write protect
       mechanisms used to protect a hard drive.

       The Fish Virus is a modified version of the 4096 Virus, though it is
       more sophisticated in that it constantly re-encrypts itself in
       system memory.  Viewing system memory with the virus resident will
       show that the names of several fish are present.

       It is unknown what the Fish virus does when it activates, though it
       does appear to check to determine if the year of the system time is
       1991.


 Virus Name:  Flash
 Aliases:
 V Status:    Rare
 Discovered:  July 1990
 Symptoms:    .COM & .EXE growth, decrease in available free memory,
              video screen flicker
 Origin:      West Germany
 Eff Length:  688  Bytes
 Type Code:   PRfA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V64+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 2.01+, NAV, or Delete infected files
 General Comments:
       The Flash Virus was discovered in July 1990 in West Germany.  Flash
       is a memory resident generic file infector, and will infect .COM and
       .EXE files, but not COMMAND.COM.

       The first time a program infected with the Flash Virus is executed,
       the virus will install itself memory resident.   976 bytes will be
       allocated in high memory, and available free memory will decrease by
       a corresponding 976 bytes.  A mapping of memory will also indicate
       that when Flash is resident in memory, interrupts 00, 23, 24, 30,
       ED, F5, and FB are now in free memory.  Total system memory reported
       by DOS, as well as low memory used by the operating system and TSRs
       will not have changed.

       Once Flash is memory resident, each time a .COM or .EXE program is
       executed it is a candidate for infection.  An uninfected .EXE program
       will always be infected upon execution.  Uninfected .COM files are
       only infected if they are greater than approximately 500 bytes in
       length.  Infected files will always increase in length by 688 bytes.

       After June of 1990, systems with a graphics capable monitor may notice
       a screen flicker occurring at approximately seven minute intervals.
       The virus causes this effect by manipulating some screen blanking bits
       every seven minutes.


 Virus Name:  Flip
 Aliases:
 V Status:    Rare
 Discovered:  July 1990
 Symptoms:    .COM & .EXE growth; decrease in system and free memory;
              boot sector and partition table altered; file allocation errors
 Origin:      West Germany
 Eff Length:  2,343  Bytes
 Type Code:   PRhABKX - Parasitic Resident .COM, .EXE, Partition Table Infector
 Detection Method:  ViruScan V66+, F-Prot 1.12+, Pro-Scan 2.01+, NAV,
              IBM Scan 2.00+
 Removal Instructions: Clean-Up V71+, Scan/D, or Delete infected files
 General Comments:
       The Flip Virus was discovered in West Germany in July 1990.  It is
       a generic file infector, and will infect .COM, .EXE, and overlay files.
       This virus will also infect COMMAND.COM, as well as alter the partition
       table and boot sector of hard disks.  It is important to note that the
       Flip virus is not infective from .COM files or boot sectors.

       The first time an EXE program infected with the Flip Virus is executed,
       it installs itself memory resident in high memory.  System memory as
       reported by the CHKDSK command as well as free memory will have
       decreased by 3,064 bytes.  At this time, the copy of COMMAND.COM
       located in the C: drive root directory will be infected, though no
       file length change will be apparent with the virus in memory.  The
       system's hard disk partition table and boot sector will also be
       slightly modified.  If the infected program was executed from a
       floppy, COMMAND.COM on the floppy will be infected, though the size
       change will be noticeable.

       After Flip becomes memory resident, any .COM or .EXE files executed
       will become infected.  Infected programs will show a file length
       increase of 2,343 bytes.  If a program is executed which uses an
       overlay file, the overlay file will also become infected.

       Systems infected Flip may experience file allocation errors resulting
       in file linkage errors.  Some data files may become corrupted.

       On the second of any month, systems which were booted from an infected
       hard disk and have an EGA or VGA capable display adapter may experience
       the display on the system monitor being horizontally "flipped" between
       16:00 and 16:59.

       Flip can only be passed between systems on infected .EXE files.
       Infected .COM files, and altered floppy boot sectors do not transfer
       the virus.

       Known variant(s) of Flip include:
       Flip B : Similar to the original Flip Virus, this variant has an
                effective length of 2,153 bytes.  Its memory resident portion
                at the top of system memory is 2,672 bytes.  The major
                difference between this variant and the original virus is
                that Flip B can infect programs from the hard disk partition
                table infection.
                Isolated: January, 1991.  Origin: Unknown.

 Virus Name:  FORM-Virus
 Aliases:     Form, Form Boot
 V Status:    Rare
 Discovered:  June 1990
 Symptoms:    BSC, clicking noise from system speaker
 Origin:      Switzerland
 Eff Length:  N/A
 Type Code:   BR - Resident Boot Sector Infector
 Detection Method:  ViruScan V64+, F-Prot 1.12+, VirHunt 2.0+, NAV
 Removal Instructions: MDisk, NAV, or DOS SYS command
 General Comments:
       The Form, or Form Boot, Virus is a memory resident infector of
       floppy and hard disk boot sectors.  It was originally isolated in
       Switzerland.

       When a system is first booted with a diskette infected with the
       Form Boot virus, the virus will infect system memory as well as
       seek out and infect the system's hard disk.  The floppy boot may
       or may not be successful, on the author's test system, a boot
       from floppy diskette infected with Form Boot never succeeded,
       instead the system would hang.  It should be noted that the virus
       was received by the author of this document as a binary file, and
       it may have been damaged in some way.

       The following text message is contained in the Form Boot virus binary
       code as received by the author of this document:

            "The FORM-Virus sends greetings to everyone who's reading
             this text.FORM doesn't destroy data! Don't panic! Fuckings
             go to Corinne."

       These messages, however, may not appear in all cases.  For example,
       I did not find these messages anywhere on a hard disk infected with
       Form Boot.

       Systems infected with the FORM-Virus in memory may notice that a
       clicking noise may be emitted from the system speaker on the 24th
       day of any month.

       This virus can be removed with the same technique as used with many
       boot sector infectors.  First, power off the system and then boot
       from a known clean write-protected boot diskette.  The DOS SYS
       command can then be used to recreate the boot sector.  Alternately,
       MDisk from McAfee Associates may be used to recreate the boot
       sector.


 Virus Name:  Frere Jacques
 Aliases:     Frere Virus
 V Status:    Rare
 Discovered:  May 1990
 Symptoms:    .COM & .EXE growth, available memory decreases, system hangs,
              music (Frere Jacques) on Fridays
 Origin:      California, USA
 Eff Length:  1,808 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V63+, Pro-Scan 1.4+, F-Prot 1.12+, NAV,
              IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 1.4+, NAV, or Delete infected files
 General Comments:
       The Frere Jacques Virus was isolated in May, 1990.  It is a memory
       resident generic file infector, infecting .COM, .EXE, and Overlay
       files.  It does not infect COMMAND.COM.  This virus is based on
       the Jerusalem B Virus.

       The first time an infected program is executed, the virus will
       install itself memory resident in low available free memory.
       The memory resident virus occupies 2,064 bytes, and attaches itself
       to interrupt 21.  After becoming memory resident, Frere Jacques will
       infect any program which is then executed.  Infected programs will
       increase in size by between 1,808 bytes and 1,819 bytes, though
       .COM files always increase in size by 1,813 bytes.

       Systems infected with Frere Jacques will experience a decrease in
       available free memory, as well as executable files increasing in
       size.  System hangs will also intermittently occur when the virus
       attempts to infect programs, thus resulting in the possible loss
       of system data.

       On Fridays, the Frere Jacques virus activates, and will play the
       tune Frere Jacques on the system speaker.

       Also see: Jerusalem B


 Virus Name:  Friday The 13th COM Virus
 Aliases:     COM Virus, Miami, Munich, South African, 512 Virus, Virus B
 V Status:    Extinct
 Discovered:  November, 1987
 Symptoms:    .COM growth, floppy disk access, file deletion
 Origin:      Republic of South Africa
 Eff Length:  512 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, Pro-Scan 1.4+, VirHunt 2.0+, F-Prot, or NAV
 General Comments:
       The original Friday The 13th COM virus first appeared in
       South Africa in 1987.  Unlike the Jerusalem (Friday The 13th)
       viruses, it is not memory resident, nor does it hook any
       interrupts.  This virus only infects .COM files, but not
       COMMAND.COM.  On each execution of an infected file, the
       virus looks for two other .COM files on the C drive and 1
       on the A drive, if found they are infected.  This virus is
       extremely fast, and the only indication of propagation occurring
       is the access light being on for the A drive, if the current
       default drive is C.  The virus will only infect a .COM file
       once.  The files, after infection, must be less than 64K in
       length.

       On every Friday the 13th, if the host program is executed, it
       is deleted.

       Known variants of the Friday The 13th COM virus are:
       Friday The 13th-B: same, except that it will infect every
            file in the current subdirectory or in the system path if
            the infected .COM program is in the system path.
       Friday The 13th-C: same as Friday The 13th-B, except that the
            message "We hope we haven't inconvenienced you" is
            displayed whenever the virus activates.

       Author's note: All samples of this virus that are available were
       created by reassembling a disassembly of this virus.  These viruses
       may not actually exist "in the wild".


 Virus Name:  Frog's Alley
 Aliases:     Frog
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM growth; Message; FAT & Directory damage; programs disappear;
              Disk Volume Label change; long disk access times
 Origin:      USA
 Eff Length:  1,500 Bytes
 Type Code:   PRCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V76+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Frog's Alley Virus was submitted in March, 1991 by David Grant of
       the United States.  This virus is a memory resident infector of .COM
       files, including COMMAND.COM.

       When the first program infected with Frog's Alley is executed, this
       virus will install itself memory resident in low, unreserved system
       memory.  Interrupts 09, 20, 21, and 2F will be hooked by the virus.
       At this time, Frog's Alley will also infect COMMAND.COM and one other
       .COM file in the current directory.

       After becoming memory resident, Frog's Alley will infect 1 .COM file
       each time an infected program is executed or a DIR command is
       performed.  In either case, long disk accesses will be noticable either
       when an infected .COM program is executed, or as the DIR command
       completes.  .COM files are only infected if their original file length
       was 1,500 or more bytes.

       Programs infected with Frog's Alley will have a file size increase of
       1,500 bytes, and the file's date and time in the disk directory will
       have been updated to the system date and time when the infection
       occurred.  The virus will be located at the beginning of infected
       programs.

       Frog's Alley activates on the 5th day of any month.  When an infected
       program is executed on the 5th, the following message will be displayed:

     (V) AIDS R.2A - Welcome to Frog's Alley !, (c) STPII Laboratory - Jan 1990

       This message will again be displayed whenever a DIR command is
       performed.  The first time the message is displayed, the virus will
       remove the system files and COMMAND.COM from the disk.  Other programs
       will still be accessible until they are also removed, or the virus is
       no longer in memory.  Once the virus is no longer in memory, the disk
       will display the volume label "s Alley !" and have no files found when
       a DIR command is performed.  The disk's FAT and root directory will have
       been overwritten with the above message multiple times.

       Other symptom's of Frog's Alley are long disk access times when
       executing programs or performing DIR commands, as well as occassional
       unexpected accesses to the B: disk drive.  Some memory intensive
       applications will hang when Frog's Alley is active in memory.


 Virus Name:  Fu Manchu
 Aliases:     2080, 2086
 V Status:    Rare
 Discovered:  March, 1988
 Symptoms:    .SYS, .BIN, .COM & .EXE growth, messages
 Origin:
 Eff Length:  2,086 (COM files) & 2,080 (EXE files) bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions: Scan/D, F-Prot, Pro-Scan 1.4+, VirHunt 2.0+, VirexPC,
              NAV
 General Comments:
       The Fu Manchu virus attaches itself to the beginning of .COM
       files or the end of .EXE files.  This virus will infect any
       executable program, including overlay, .SYS, and .BIN files
       as well.  It appears to be a rewritten version of the Jerusalem
       virus, with a possible creation date of 3/10/88.

       A marker or id string usually found in this virus is
       'sAXrEMHOr', though the virus only uses the 'rEMHOr' portion
       of the string to identify infected files.

       One out of sixteen infections will result in a timer being
       installed, and after a random amount of time, the message
       "The world will hear from me again!" is displayed and
       the system reboots.  This message will also be displayed on
       an infected system after a warm reboot, though the virus doesn't
       survive in memory.

       After August 1, 1989, the virus will monitor the keyboard buffer,
       and will add derogatory comments to the names of various
       politicians.  These comments go to the keyboard buffer, so
       their effect is not limited to the display.  The messages within
       the virus are encrypted.

       This virus is very rare in the United States.

       Also see: Jerusalem B, Taiwan 3


 Virus Name:  Ghostballs
 Aliases:     Ghost Boot, Ghost COM
 V Status:    Extinct
 Discovered:  October, 1989
 Symptoms:    moving graphic display, .COM file growth, file corruption, BSC.
 Origin:      Iceland
 Eff Length:  2,351 bytes
 Type Code:   PNCB - Parasitic Non-Resident .COM & Boot Sector Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: MDisk or DOS SYS and erase infected .COM files,
              or CleanUp, F-Prot, Pro-Scan 1.4+, VirexPC, Scan/D/X,
              VirHunt 2.0+, NAV
 General Comments:
       The Ghostball virus (Ghost Boot and Ghost COM) were discovered in
       October, 1989 by Fridrik Skulason of Iceland.  The Ghostballs Virus
       virus infects generic .COM files, increasing the file size by
       2,351 bytes.  It also alters the disk boot sector, replacing it
       with viral code similar to the Ping Pong virus.  This altered
       boot sector, however, will not replicate.

       Symptoms of this virus are very similar to the Ping Pong
       virus, and random file corruption may occur on infected
       systems.

       The Ghostballs virus was the first known virus that could infect
       both files (.COM files in this case) and disk boot sectors.
       After the boot sector is infected, the system experiences the
       bouncing ball effect of the Ping Pong virus.  If the boot sector
       is overwritten to remove the boot viral infection, it will again
       become corrupted the next time an infected .COM file is executed.

       The Ghostballs Virus is based on the code of two other viruses.
       The .COM infector portion consists of a modified version of the
       Vienna virus.  The boot sector portion of the virus is based on
       the Ping Pong virus.

       To remove this virus, turn off the computer and reboot from
       a write protected master diskette for the system.  Then
       use either MDisk or the DOS SYS command to replace the boot
       sector on the infected disk.  Any infected .COM files must
       also be erased and deleted, then replaced with clean copies
       from your original distribution diskettes.


 Virus Name:  Golden Gate
 Aliases:     Mazatlan, 500 Virus
 V Status:    Extinct
 Discovered:  1988
 Symptoms:    BSC, disk format, Resident TOM
 Origin:      California, USA
 Eff Length:  N/A
 Type Code:   BRt - Resident Boot Sector Infector
 Detection Method:  ViruScan (identifies as Alameda)
 Removal Instructions: MDisk, F-Prot, or DOS SYS command
 General Comments:
       The Golden Gate virus is a modified version of the Alameda virus
       which activates when the counter in the virus has determined
       that it is infected 500 diskettes.  The virus replicates when
       a CTL-ALT-DEL is performed, infecting any diskette in the floppy
       drive.  Upon activation, the C: drive is formatted.  The
       counter in the virus is reset on each new floppy or hard drive
       infected.

       Known Variants of this virus are:
       Golden Gate-B: same as Golden Gate, except that the counter
           has been changed from 500 to 30 infections before
           activation, and only diskettes are infected.
       Golden Gate-C: same as Golden Gate-B, except that the hard
           drive can also be infected.  This variant is also known
           as the Mazatlan Virus, and is the most dangerous of the
           Golden Gate viruses.

       Also see: Alameda


 Virus Name:  Green Peace
 Aliases:
 V Status:    New
 Discovered:  April, 1991
 Symptoms:    .EXE files overwritten; Message displayed; System Hangs;
              Additional files located on disk; File Date/Time Changes
 Origin:      United States
 Eff Length:  15,022 Bytes
 Type Code:   ONE - Overwriting Non-Resident .EXE Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The Green Peace Virus was received in April 1991 from a United States
       source.  This virus is a non-resident overwriting virus which infects
       .EXE programs.  It is a research virus, its original source, as well
       as an infected .COM file arrived as the original submission.

       When a program infected with Green Peace is infected, the virus will
       infect all .EXE programs located in the current directory by overwriting
       the first 15,022 bytes with the virus.  If the .EXE program was
       originally smaller than 15,022 bytes, its length on infection will be
       15,022 bytes.  Larger files will not have any file size increase.  The
       date and time of infected files will be updated to the system date and
       time when infection occurred.  All infected .EXE files will contain
       the following text near the beginning of the program:

               "Green PeaceGreen Peace"

       After infecting all of the .EXE files in the current directory, the
       virus will then scroll the system display and display the message
       "Green Peace" in the middle of the screen.  The system will then
       appear to be hung until Ctrl-C is hit several times.

       Two additional files can be found in disk directories containing
       programs infected with Green Peace.  These files are named INH and
       7.EXE.  The INH file contains a list of all files in the current
       directory which are infected.  7.EXE contains a pure copy of the
       Green Peace virus.

       The original sample received of this virus is a .COM file which
       "drops" the Green Peace Virus.  It does not contain the above text
       string, but instead contains the text string "GREEN".

       Green Peace does not do anything besides replicate (overwriting its
       host) and displaying its message.


 Virus Name:  Gremlin
 Aliases:     Greemlin
 V Status:    New
 Discovered:  May, 1991
 Symptoms:    .COM & .EXE growth; System slowdown; File dates may disappear
 Origin:      Unknown
 Eff Length:  1,146 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  IBM Scan 2.00+
 Removal Instructions: Delete infected files
 General Comments:
       The Gremlin, or Greemlin, Virus was submitted in May, 1991 by the
       PCVRF.  This virus is a memory resident infector of .COM and .EXE files,
       including COMMAND.COM.  Its origin is unknown.

       The first time a program infected with Gremlin is executed, the virus
       was install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  Interrupt 12's return is not moved.  The
       virus will hook interrupts 08 and 21.

       Once Gremlin is memory resident, it will infect .COM and .EXE files
       when they are executed.  If COMMAND.COM is executed, it will become
       infected.  Infected files increase in length by 1,146 bytes with the
       virus being located at the end of the program.  The increase in file
       length will be hidden by the virus if Gremlin is memory resident.
       The program's time in the disk directory will disappear if it was
       originally 12:00A.

       The text string "greemlin" can be found in all infected programs.

       Infected systems may notice a slight slowdown in speed of approximately
       10%.

       It is unknown what Gremlin does besides replicate.


 Virus Name:  Grither
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; C: & D: drive disk corruption
 Origin:      United States
 Eff Length:  774 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan V72+, IBM Scan 2.00+
 Removal Instructions: Scan/D, Delete infected files
 General Comments:
       The Grither Virus was submitted in January, 1991, by Paul Ferguson
       of the United States.  This virus is a non-resident direct action
       infector of .COM files, including COMMAND.COM.

       When a program infected with Grither is executed, the virus will infect
       one .COM file in the current directory.  COMMAND.COM may become
       infected if it exists in the current directory.

       .COM programs infected with Grither will increase in length by 774
       bytes, the virus will be located at the end of the infected file.  The
       file's date and time in the disk directory will not be altered by the
       virus.

       The Grither Virus can be extremely destructive.  With a probability of
       approximately one out of every eight times an infected program is
       executed, the virus may activate.  On activation, Grither will overwrite
       the beginning of the C: and D: drives of the system's hard disk.
       Effectively, this corrupts the disk's boot sector, file allocation
       tables, and directory, as well as the system files.

       Grither is roughly based on the Vienna and Violator viruses.

       ViruScan V72 will identify Grither infected files as Vienna B, though
       it may also identify them as Violator in rare circumstances.


 Virus Name:  Groen Links
 Aliases:     Green Left
 V Status:    Rare
 Discovered:  March, 1990
 Symptoms:    .COM & .EXE growth; TSR; Music
 Origin:      Amsterdam, Holland
 Eff Length:  1,888 Bytes
 Type Code:   PRsA - Resident Parasitic .COM &.EXE Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The Groen Links Virus was originally reported in Amsterdam, Holland,
       in March 1990.  This virus is a memory resident infector of .COM and
       .EXE files.  It does not infect COMMAND.COM.  It is a variant of the
       Jerusalem B virus, though is listed separately here as it is a different
       length and exhibits different characteristics.

       The first time a program infected with the Groen Links Virus is
       executed, the virus will install itself memory resident as a low
       system memory TSR of 1,872 bytes.  Interrupts 21 and CE will be hooked
       by the virus.

       After the virus is memory resident, it will infect .COM and .EXE files
       as they are executed.  Infected .COM files will increase in length
       by 1,893 bytes with the virus being located at the beginning of the
       file.  .EXE files will increase in length by 1,888 to 1,902 bytes with
       the virus located at the end of infected files.  As with many of the
       Jerusalem variants, this virus will reinfect .EXE files.  After the
       first infection, .EXE files will increase by 1,888 bytes on subsequent
       infections.  Infected files will contain the text string: "GRLKDOS".

       After the virus has been resident for 30 minutes, it may play
       "Stem op Groen Links" every 30 minutes.  The name of the tune translates
       to "Vote Green Left", Green Left being a political party in Holland.


 Virus Name:  Guppy
 Aliases:
 V Status:    Rare
 Discovered:  October, 1990
 Symptoms:    TSR, .COM growth, error messages, disk boot failures
 Origin:      United States
 Eff Length:  152 Bytes
 Type Code:   PRsCK - Resident Parasitic .COM &.EXE Infector
 Detection Method: Pro-Scan 2.01+, ViruScan V76+, IBM Scan 2.00+
 Removal Instructions: Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The Guppy Virus was submitted in late October, 1990 by Paul Ferguson
       of Washington, DC.  Guppy is a memory resident infector of .COM files,
       including COMMAND.COM.

       The first time a program infected with the Guppy Virus is executed, the
       virus will install itself memory resident as a low system memory TSR
       with interrupt 21 hooked.  Available free memory will decrease by
       720 bytes.

       After the virus is memory resident, any .COM file with a file length of
       at least 100 bytes (approximately) that is executed will become infected
       with Guppy.  Infected files will increase in length by 152 bytes, with
       two bytes added to the beginning of the .COM file, and 150 bytes added
       to the end of the file.  Infected files will also have their date/time
       stamps in the directory updated to the system date and time when the
       infection occurred.

       If COMMAND.COM is executed with Guppy memory resident, it will become
       infected.  If the system is later booted from a disk with a Guppy
       infected COMMAND.COM, the boot will fail and a "Bad or Missing Command
       Interpreter" message will be displayed.

       Some programs will also fail to execute properly once infected with
       Guppy.  For example, attempts to execute EDLIN.COM after it was
       executed on my system resulted in a consistent "Invalid drive or
       file name" message, and EDLIN ending execution.

       Infected files can be identified as they will end with the following
       hex character string: 3ECD211F5A5B58EA

       Known variant(s) of Guppy include:
       Guppy-B:  Almost identical to Guppy, there are a few bytes which have
                 been altered in this variant.


 Virus Name:  Halloechen
 Aliases:
 V Status:    Rare
 Discovered:  October, 1989
 Symptoms:    TSR, .COM & .EXE growth, garbled keyboard input.
 Origin:      West Germany
 Eff Length:  2,011 Bytes
 Type Code:   PRsA - Resident Parasitic .COM &.EXE Infector
 Detection Method:  ViruScan V57+, Pro-Scan 1.4+, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: VirHunt 2.0+, Scan/D, NAV, or delete infected files
 General Comments:
       The Halloechen virus was reported by Christoff Fischer of
       the University of Karlsruhe in West Germany.  The virus is
       a memory resident generic .COM & .EXE file infector which is
       reported to be widespread in West Germany.

       The Halloechen virus installs itself memory resident when the
       first infected program is executed.  Thereafter, the virus will
       infect any .EXE or .COM file which is run unless the resulting
       infected file would be greater than 64K in size, or the file's
       date falls within the system date's current month and year.
       Once a file has been determined to be a candidate for infection,
       and is less than approximately 62K in size as well as having a
       date outside of the current month and year, it is infected.
       In the process of infecting the file, the files size is first
       increased so that it is a multiple of 16 (ends on a paragraph
       boundary), then the 2,011 bytes of viral code are added.

       When infected files are run, input from the keyboard is garbled.


 Virus Name:  Happy New Year
 Aliases:     Happy N.Y., V1600
 V Status:    Rare
 Discovered:  December, 1989
 Symptoms:    TSR; .COM & .EXE Growth; Floppy Boot Sector altered;
              Boot failures; Bad or missing command interpretor message
 Origin:      Bulgaria
 Eff Length:  1,600 Bytes
 Type Code:   PRsAK - Resident Parasitic .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Happy New Year, or V1600, Virus was submitted in December, 1990.
       This virus is originally from Bulgaria, and is a memory resident
       infector of .COM and .EXE files.  It will infect COMMAND.COM.

       The first time a program infected with the Happy New Year Virus is
       executed, the virus will install itself memory resident as a 2,432
       bytes low system memory TSR.  Interrupt 21 will be hooked by the
       virus.  At this time, the virus will also make a slight alteration
       to the floppy boot sector, and infect COMMAND.COM.  Infected
       COMMAND.COM files will not show a file length increase as the virus
       will overwrite a portion of the hex 00 section of the file.  The
       altered floppy boot sector does not contain a copy of the virus, and
       is not infectious.

       Once Happy New Year is memory resident, it will infect .COM and .EXE
       programs as they are executed.  Infected programs will increase in
       length by 1,600 bytes and have the virus located at the end of the
       infected file.

       The following text message can be found in infected programs:

               "Dear Nina, you make me write this virus; Happy new year!"
               "1989"

       This message is not displayed by the virus.

       Systems infected with the Happy New Year Virus may fail to boot,
       receiving a "Bad or missing command interpretor" message if COMMAND.COM
       is infected on the boot diskette or hard drive.

       It is unknown if Happy New Year carries any destructive capabilities.

       Known variant(s) of Happy New Year are:
       Happy New Year B : Similar to Happy New Year, this variant has five
               bytes which differ from the original virus.  Unlike Happy
               New Year, COMMAND.COM will only be infected if it is executed
               for some reason.


 Virus Name:  HIV
 Aliases:
 V Status:    Research
 Discovered:  March, 1991
 Symptoms:    .COM & .EXE growth; decrease in total system & available memory
 Origin:      Italy
 Eff Length:  1,614 Bytes
 Type Code:   PRhAK - Resident Parasitic .COM & .EXE Infector
 Detection Method:  ViruScan V76+
 Removal Instructions: CleanUp V77+, or Delete infected files
 General Comments:
       The HIV Virus was submitted in March, 1991, by David Grant of the
       United States, whom received it from Italy.  This virus is based on the
       Murphy Virus, and is a memory resident infector of .COM and .EXE files,
       as well as COMMAND.COM.

       When a program infected with HIV is executed, HIV will check to see if
       it is already present in memory.  If it is not already memory resident,
       it will install itself at the top of system memory but below the 640K
       DOS boundary.  Interrupt 21 will be hooked by the virus, and total
       system memory and available free memory as measured by the DOS ChkDsk
       program will decrease by 1,632 bytes.

       After becoming memory resident, HIV will infect .COM and .EXE files
       when they are executed or openned for any reason.  Infected programs
       will increase in size by 1,614 bytes with the virus being located at
       the end of infected files.  The file date and time in the disk
       directory will not be altered.

       Programs infected with HIV will contain the following text strings:

               "HIV Virus - Release 1.0
                Created by Cracker Jack
                (C) 1991 Italian Virus Laboratory"

       It is not known what HIV does besides replicate.  This virus may also
       be a research virus and not in the public domain since the original
       sample submitted is not a natural infection of the virus.

       Also see: Murphy


 Virus Name:  Holland Girl
 Aliases:     Sylvia
 V Status:    Rare
 Discovered:  December, 1989
 Symptoms:    .COM growth, TSR
 Origin:      Netherlands
 Eff Length:  1,332 Bytes
 Type Code:   PRsC - Resident Parasitic .COM Infector
 Detection Method:  ViruScan V50+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: F-Prot, Pro-Scan 1.4+, VirHunt 2.0+, or Scan/D
 General Comments:
       The Holland Girl or Sylvia Virus was first reported by Jan
       Terpstra of the Netherlands.  This virus is memory resident
       and infects only .COM files, increasing their size by 1,332
       bytes.  The virus apparently does no other damage, and
       does not infect COMMAND.COM.

       The virus's name is due to the fact that the virus code
       contains the name and phone number of a girl named Sylvia
       in Holland, along with her address, requesting that post cards
       be sent to her.  The virus is believed to have been written
       by her ex-boyfriend.

       Also see: Holland Girl 2


 Virus Name:  Holland Girl 2
 Aliases:     Sylvia 2
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth
 Origin:      New Brunswick, Canada
 Eff Length:  1,332 Bytes
 Type Code:   PNC - Resident Parasitic .COM Infector
 Detection Method: ViruScan V76+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Holland Girl 2, or Sylvia 2, Virus was discovered in New Brunswick,
       Canada in January 1991.  This virus is similar to the Holland Girl
       Virus, though it has been altered significantly.  This virus is a non-
       resident infector of .COM files, including COMMAND.COM.

       When a program infected with the Holland Girl 2 Virus is executed, the
       virus will infect up to four .COM files.  It first checks the C: drive
       root directory to look for candidate files, then the current drive and
       current directory.

       .COM Programs infected with the Holland Girl 2 Virus will increase in
       length by 1,332 bytes with the virus being located at the beginning of
       the infected program.  Infected programs will also contain the following
       text:

               "This program is infected by a HARMLESS Text-Virus V2.1"

               "Send a FUNNY postcard to : Sylvia"

                "You might get an ANTIVIRUS program....."

       Sylvia's last name, and full address are in the virus in plain text,
       and are not repeated here for privacy reasons.

       Also see: Holland Girl


 Virus Name:  Holocaust
 Aliases:     Stealth, Holo
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    decrease in system & available memory; file allocation errors
 Origin:      Barcelona, Spain
 Eff Length:  3,784 Bytes
 Type Code:   PRhCK - Resident Parasitic .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Holocaust Virus was submitted in December, 1990 by David Llamas of
       Barcelona, Spain.  Holocaust is a self-encrypting memory resident
       infector of .COM files, including COMMAND.COM.  This virus is qualifies
       as a Stealth virus as it hides the file length increase on infected
       files as well as infecting on file open and execution.

       The first time a program infected with the Holocaust Virus is
       executed, the virus will install itself memory resident.  It will
       reserve 4,080 bytes of high system memory below the 640K DOS boundary.
       This memory will be marked as Command Data, and interrupt 21 will be
       hooked.  Some memory mapping utilities will show the memory resident
       command interpretor to have grown by the 4,080 bytes, though it is
       actually in high memory instead of low memory.

       Once Holocaust is memory resident, it will infect COM programs which
       are executed or openned for any reason.  This virus, however, will not
       infect very small COM files of less than 1K in size.  Infected COM
       programs will increase in size by 3,784 bytes, though this file size
       increase will not be seen in a directory listing if the virus is
       memory resident.   The viral code will be located at the end of
       infected files.

       If the Holocaust Virus is memory resident and the DOS ChkDsk command
       is executed, infected files will be indicated as having a file
       allocation error.  Execution of the command with the /F parameter on
       systems with the virus memory resident will result in the infected
       files becoming damaged.  The file allocation errors do not occur if
       the virus is not in memory since at that time the directory size will
       match the file allocation in the FAT.

       The Holocaust Virus is a self-encrypting virus, and will occasionally
       produce an infected file which is encrypted differently from its
       original encryption mechanism.  Some infected files will contain the
       following text at the end of the program, while other samples will have
       this text encrypted:

               "Virus Anti - C.T.N.E. v2.10a. (c)1990 Grupo Holokausto.
                Kampanya Anti-Telefonica. Menos tarifas y mas servicio.
                Programmed in Barcelona (Spain). 23-8-90.
                - 666 -"

       Holocaust is reported by David Llamas to be widespread in Barcelona
       as of December, 1990.  It is not known if this virus activates, and
       what it does on activation.  It does not match a similar virus
       reported by Jim Bates of the United Kingdom named Spanish Telecom.


 Virus Name:  Hybryd
 Aliases:     Hybrid
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth
 Origin:      Poland
 Eff Length:  1,306 Bytes
 Type Code:   PRhA - Resident Parasitic .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Hybryd Virus was submitted in January, 1991, and is from Poland.
       This virus is a non-resident direct action infector of .COM files,
       including COMMAND.COM.

       When a program infected with Hybryd is executed, the virus will
       look for an uninfected .COM program in the current directory.  If an
       uninfected program is found, the virus will infect it.  Infected
       .COM programs will have a file length increase of 1,306 bytes, the
       virus will be located at the end of the infected program.  This virus
       alters the file time so that the seconds field in the file time is 62,
       the indicator that the file is infected.  Just viewing the directory,
       though, it appears that the file date and time has not been altered.

       The following text strings are contained within the Hybryd Virus, though
       they cannot be viewed in infected files as they are encrypted:

               "(C) Hybryd Soft
                Specjalne podziekowania dla
                Andrzeja Kadlofa i Mariusza Deca
                za artykuly w Komputerze 11/88"

       In the submitted sample, the one text string that is not encrypted is
       the following, which is also found in replicated samples:

               "Copyright IBM Corp 1981,1987
                Licensed Material - Program Property of IBM"

       This string should not be taken to indicate that IBM necessarily had
       anything to do with the creation of this virus.

       On Friday The 13ths starting in 1992, this virus will overwrite the
       current drive's boot sector when an infected program is executed.  It
       may also corrupt program files at that time when they are executed.


 Virus Name:  Hymn
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM & .EXE growth; decrease in system and available free memory
 Origin:      USSR
 Eff Length:  1,865 Bytes
 Type Code:   PRhA - Resident Parasitic .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Hymn Virus was submitted in December, 1990, and originated in the
       USSR.  This virus is a memory resident infector of .COM and .EXE files,
       and will infect COMMAND.COM.

       The first time a program infected with the Hymn Virus is executed, the
       virus will install itself memory resident at the top of system memory
       but below the 640K DOS boundary.  The DOS ChkDsk program will show that
       total system memory and available free memory have decreased by 3,712
       bytes.  This virus does not move the interrupt 12 return.  COMMAND.COM
       will also become infected at this time.

       Once Hymn is memory resident, it will infect .COM and .EXE files which
       are over approximately 2K in length when they are executed or openned
       for any reason.  Infected .COM files will increase in length by
       1,865 bytes.  Infected .EXE files will have a file length increase of
       1,869 to 1,883 bytes.  In both cases the virus will be located at the
       end of the infected file.

       Infected programs will contain two text strings within the viral code:
               "ibm@SNS"
               "@ussr@"

       It is not known what Hymn does when it activates, but it is assumed
       from the name that under some conditions it may play music.


 Virus Name:  Icelandic
 Aliases:     656, One In Ten, Disk Crunching Virus, Saratoga 2
 V Status:    Extinct
 Discovered:  June, 1989
 Symptoms:    .EXE growth, Resident TOM, bad sectors, FAT corruption
 Origin:      Iceland
 Eff Length:  656 bytes
 Type Code:   PRfE - Resident Parasitic .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, Pro-Scan, VirexPC, AVTK 3.5+
              VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, Pro-Scan 1.4+, VirexPC 1.1B, F-Prot,
              VirHunt 2.0+, NAV
 General Comments:
       The Icelandic, or "Disk Crunching Virus", was originally
       isolated in Iceland in June 1989.  This virus only infects
       .EXE files, with infected files growing in length between
       656 and 671 bytes.  File lengths after infection will always
       be a multiple of 16.  The virus attaches itself to the end
       of the programs it infects, and infected files will always
       end with hex '4418,5F19'.

       The Icelandic virus will copy itself to the top of free memory
       the first time an infected program is executed.  Once in high
       memory, it hides from memory mapping programs.  If a program
       later tries to write to this area of memory, the computer will
       crash.  If the virus finds that some other program has "hooked"
       Interrupt 13, it will not proceed to infect programs.  If
       Interrupt 13 has not been "hooked", it will attempt to infect
       every 10th program executed.

       On systems with only floppy drives, or 10 MB hard disks, the
       virus will not cause any damage.  However, on systems with
       hard disks larger than 10 MB, the virus will select one unused
       FAT entry and mark the entry as a bad sector each time it
       infects a program.

       Also see: Icelandic-II, Icelandic-III, Mix/1, Saratoga


 Virus Name:  Icelandic-II
 Aliases:     System Virus, One In Ten
 V Status:    Extinct
 Discovered:  July, 1989
 Symptoms:    .EXE growth, Resident TOM, FAT corruption
              date changes, loss of Read-Only
 Origin:      Iceland
 Eff Length:  632 Bytes
 Type Code:   PRfE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, Pro-Scan 1.4+, VirexPC 1.1B, F-Prot,
              VirHunt 2.0+, NAV
 General Comments:
       The Icelandic-II Virus is a modified version of the Icelandic
       Virus, and was isolated for the first time in July 1989 in
       Iceland.  These two viruses are very similar, so only the
       changes to this variant are indicated here, refer to Icelandic
       for the base virus information.

       Each time the Icelandic-II virus infects a program, it will
       modify the file's date, thus making it fairly obvious that
       the program has been changed.  The virus will also remove
       the read-only attribute from files, but does not restore it
       after infecting the program.

       The Icelandic-II virus can infect programs even if the system
       is running an anti-viral TSR that monitors interrupt 21, such
       as FluShot+.

       On hard disks larger than 10 MB, there are no bad sectors
       marked in the FAT as there is with the Icelandic virus.

       Also see: Icelandic, Icelandic-III, Mix/1, Saratoga


 Virus Name:  Icelandic-III
 Aliases:     December 24th
 V Status:    Endangered
 Discovered:  December, 1989
 Symptoms:    .EXE growth, Resident TOM, bad sectors, FAT corruption,
              Dec 24 message.
 Origin:      Iceland
 Eff Length:  853 Bytes
 Type Code:   PRfE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: F-Prot, Scan/D/X, Pro-Scan 1.4+, VirexPC 1.1B,
              VirHunt 2.0+, NAV, or delete infected files
 General Comments:
       The Icelandic-III Virus is a modified version of the Icelandic
       Virus, and was isolated for the first time in December 1989 in
       Iceland.  These two viruses are very similar, so only the
       changes to this variant are indicated here, refer to Icelandic
       for the base virus information.

       The Icelandic-III virus's id string in the last 2 words of the
       program is hex '1844,195F', the bytes in each word being
       reversed from the id string ending the Icelandic and
       Icelandic-II viruses.  There are also other minor changes to
       the virus from the previous Icelandic viruses, including the
       addition of several NOP instructions.

       Before the virus will infect a program, it checks to see if the
       program has been previously infected with Icelandic or
       Icelandic-II, if it has, it does not infect the program.
       Files infected with the Icelandic-III virus will have their
       length increased by between 848 and 863 bytes.

       If an infected program is run on December 24th of any year,
       programs subsequently run will be stopped, later displaying
       the message "Gledileg jol" ("Merry Christmas" in Icelandic)
       instead.

       Also see: Icelandic, Icelandic-II, Mix/1, Saratoga


 Virus Name:  IKV 528
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM & .EXE growth
 Origin:      Unknown
 Eff Length:  528 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The IKV 528 Virus was submitted in January, 1991, its origin and
       isolation point are unknown.  This virus is a non-resident infector
       of .COM files.  It will infect COMMAND.COM.

       When a program infected with IKV 528 is executed, the virus will
       infect two .COM programs in the current directory.  .COM programs which
       are smaller than 520 bytes will not be infected.  Infected .COM
       programs will increase in length by 528 bytes.  The virus will be
       located at the end of infected programs.  The file date and time in the
       disk directory will not be altered by the virus.

       This virus does not do anything besides replicate.


 Virus Name:  Invader
 Aliases:     Plastique Boot
 V Status:    Common
 Discovered:  September, 1990
 Symptoms:    TSR; .COM & .EXE growth; BSC; music
 Origin:      Taiwan/China
 Eff Length:  4,096 Bytes
 Type Code:   PRsAB - Parasitic Resident .COM, .EXE, & Boot Sector Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D, CleanUp V67+, or Delete infected files
 General Comments:
       The Invader Virus was isolated in September, 1990 in China.
       This virus is a later version of the Plastique-B or Plastique 5.21
       Virus.  It is a memory resident infector of .COM and .EXE files,
       but not COMMAND.COM.  It also infects boot sectors.  In September
       1990, many reports of infections of this virus have been received,
       it appears to have spread very rapidly.

       The first time a program infected with the Invader virus is
       executed, the virus will install itself memory resident as a low
       system memory TSR.  The TSR is 5,120 Bytes and interrupts 08, 09,
       13, and 21 will be hooked.

       At this time, the virus will also infect the boot sector of the drive
       where the infected program was executed.  The new boot sector is an
       MSDOS 3.30 boot sector, and can be easily identified because the
       normal DOS error messages found in the boot sector are now at the
       beginning of the boot sector instead of the end.

       After the virus has become memory resident, any .COM or .EXE file
       (with the exception of COMMAND.COM) openned will be infected by the
       virus.  Infected .COM files will increase in length by 4,096 bytes
       with the viral code being located at the beginning of the infected
       file.  .EXE files will increase in length between 4,096 and 4,110
       bytes with the viral code being located at the end of the infected
       file.

       Additionally, any non-write protected diskettes which are exposed to
       the infected system will have their boot sectors infected.

       The Invader Virus activates after being memory resident for
       30 minutes.  At that time, a melody may be played on the system
       speaker.  On systems which play the melody, it will continue until
       the system is rebooted.  The melody isn't played on 286 based systems,
       but is noticeable on the author's 386SX test machine.

       Also see: Plastique, Plastique-B


 Virus Name:  Iraqui Warrior
 Aliases:     Iraqui
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; Closely spaced beeps from system speaker;
              system hangs; boot failures
 Origin:      USA
 Eff Length:  777 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Iraqui Warrior Virus was isolated on January 17, 1991 in the
       United States.  This virus is a non-memory resident infector of .COM
       files, including COMMAND.COM.  It is based on the Vienna Virus.

       When a program infected with the Iraqui Warrior Virus is executed, the
       virus will infect one of the first four .COM files located on the
       current drive and current directory.  Infected .COM files will have
       a file length increase of 777 bytes with the virus being located at the
       end of the file.

       The following text strings can be found in infected files, the first
       two occurring near the beginning of the virus, and the last being
       located very near the end of the infected file:

               "I come to you from The Ayatollah!"
               "(c)1990, VirusMasters"
               "An Iraqui Warrior is in your computer..."

       None of these messages are displayed by the virus.

       Systems infected with the Iraqui Warrior virus may occassionally
       experience the system speaker issuing a series of closely spaced beeps
       when an infected program is executed.  When this occurs, the system
       will hang and have to be rebooted.  The beeps continue until the reboot
       occurs.

       Booting from a disk where COMMAND.COM has been infected will result in
       a "Memory allocation error, Cannot start COMMAND, exiting" message
       appearing.

       The Iraqui Warrior does not appear to do anything else besides the
       above.


 Virus Name:  Italian 803
 Aliases:     Italian File
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM & .EXE growth
 Origin:      Italy
 Eff Length:  803 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan V77+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Italian 803 Virus was submitted in March, 1991.  This virus is a
       non-resident direct action infector of .COM and .EXE files.  It will
       infect COMMAND.COM.

       When a program infected with Italian 803 is executed, the virus will
       look for an uninfected .EXE file in the current directory to infect.
       If one is found, it will become infected.  If an uninfected .EXE file
       does not exist in the current directory, the virus will then look for
       an uninfected .COM file in the current directory.  If an uninfected
       .COM file is found, it will then be infected.

       Programs infected with Italian 803 will have a file length increase
       of 803 to 817 bytes with the virus being located at the end of the
       infected file.  This virus does not alter the file date and time in the
       disk directory.

       The Italian 803 Virus may reinfect programs already infected with this
       virus.  The reinfection only occurs when an infected program is copied,
       and then another infected program is executed.  Reinfections of Italian
       803 will result in an additional 816 bytes being added to the file.

       Italian 803 does not do anything besides replicate.

       Known variant(s) of Italian 803 include:
       Italian 803-B: Similar to Italian 803, this variant differs by only
               1 byte.


 Virus Name:  Itavir
 Aliases:     3880
 V Status:    Endangered
 Discovered:  March, 1990
 Symptoms:    .EXE growth, COMMAND.COM file, Boot sector corruption
 Origin:      Italy
 Eff Length:  3,880 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method:  ViruScan V60+, Pro-Scan 1.4+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The Itavir virus was isolated in March 1990 by a group of
       students at the Milan Politechnic in Milan, Italy.  The Itavir
       virus is a non-resident generic .EXE Infector.  Infected files
       will increase in length by 3,880 bytes.  Infected systems,
       besides having files which have increased in length, will
       usually have a file with the name COMMAND.COM somewhere on
       the disk.  The first character of this file name is an
       unprintable character.  The COMMAND.COM file contains the
       pure virus code and is used for appending to files as they
       are infected.

       The Itavir virus activates at some time period after the system
       has been running for more than 24 hours.  When it activates, the
       boot sector is corrupted, rendering the system unbootable.  The
       virus also displays a message in Italian and writes ansi values
       from 0 thru 255 to all available I/O ports, thus confusing any
       attached peripheral devices.  Some monitors may show a flickering
       effect when this occurs, while some VGA monitors may actually
       "hiss".


 Virus Name:  Jeff
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM growth; overwritten sectors on hard disk
 Origin:      USA
 Eff Length:  814 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V72+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Jeff Virus was isolated in the United States in December, 1990.
       This virus is a non-resident infector of .COM files, including
       COMMAND.COM.

       When a program infected with the Jeff Virus is executed, the virus
       will attempt to infect one .COM file on the C: drive, starting in
       the root directory.  Infected .COM files will increase in size by
       814 to 828 bytes, with the virus being located at the end of the
       infected program.

       The Jeff Virus received its name from the following text string which
       is encrypted in the viral code:

               "Jeff is visiting your hard disk"

       While Jeff is visiting your hard disk, it will occasionally write
       some sectors of random memory contents to the hard disk.  If these
       sectors are written to the boot sector, partition table, or FAT, the
       contents of the disk may become inaccessible or produce unexpected
       results.


 Virus Name:  Jerk
 Aliases:     Talentless Jerk, SuperHacker
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM & .EXE growth; Message; Unexpected access to C: drive
 Origin:      Unknown
 Eff Length:  1,077 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  IBM Scan 2.00+
 Removal Instructions:  Delete infected programs
 General Comments:
       The Jerk, Talentless Jerk, or SuperHacker Virus was submitted in
       March, 1991.  Its origin is unknown.  This virus is a non-memory
       resident infector of .COM and .EXE programs, and it will infect
       COMMAND.COM.

       When a program is executed which is infected with the Jerk Virus, it
       will search the directory structure of the C: drive to find a program
       to infect.  If the user executed the infected program from a diskette,
       an unexpected access to the system hard disk will occur.  Once the
       virus has selected a .COM or .EXE program to infect, it will alter the
       first nine bytes of the candidate file, and then append the virus to the
       end of the newly infected program.  The following message may also be
       displayed on the system monitor, though this does not always occur:

      "Craig Murphy calls himself SUPERHACKER but he's just a talentless jerk!"

       This message cannot be seen within infected programs as it is
       encrypted within the virus.

       Programs infected with the Jerk Virus will have a file length increase
       of 1,077 bytes.  The text string "MURPHY" will also be found starting
       at the fourth byte of the infected file.  The other text string which
       can be found in infected files is:

               "COMMAND.COM *.COM *.EXE Bad command or file name"

       The Jerk Virus does not do anything besides replicate.


 Virus Name:  Jerusalem
 Aliases:     PLO, Israeli, Friday 13th, Russian, 1813(COM), 1808(EXE)
 V Status:    Common
 Discovered:  October, 1987
 Symptoms:    TSR, .EXE & .COM growth, system slowdown, deleted files
              on Friday 13th, "Black WIndow"
 Origin:      Israel
 Eff Length:  1,813 (COM files) & 1,808 (EXE files) bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC 1.1+,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  Scan/D/A, Saturday, CleanUp, UnVirus, F-Prot,
              VirexPC 1.1+, Pro-Scan 1.4+, NAV
 General Comments:
       The Jerusalem Virus was originally isolated at Hebrew
       University in Israel in the Fall of 1987.  Jerusalem is a memory
       resident infector of .COM and .EXE files, with .EXE file being
       reinfected each time they are executed due to a bug in the
       virus.

       This virus redirects interrupt 8, and 1/2 hour after execution
       of an infected program the system will slow down by a factor
       of 10.  Additionally, some Jerusalem Virus variants will have a
       "Black Window" or "Black Box" appear on the lower left side of
       the screen which will scroll up the screen as the screen scrolls.

       On Friday The 13ths, after the virus is installed in memory,
       every program executed will be deleted from disk.

       The identifier for some strains is "sUMsDos", however,
       this identifier is usually not found in the newer variants of
       Jerusalem.

       The Jerusalem Virus is thought to have been based on the Suriv 3.00
       Virus, though the Suriv 3.00 Virus was isolated after the Jerusalem
       Virus.

       Also see: Jerusalem B, New Jerusalem, Payday, Suriv 3.00


 Virus Name:  Jerusalem B
 Aliases:     Arab Star, Black Box, Black Window, Hebrew University
 V Status:    Common
 Discovered:  January, 1988
 Symptoms:    TSR, .EXE & .COM growth, system slowdown, deleted files
              on Friday 13th, "Black WIndow"
 Origin:      Israel
 Eff Length:  1,813 (.COM files) & 1,808 (.EXE files) bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC 1.1+,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  F-Prot, Saturday, CleanUp, UnVirus, VirexPC 1.1+
              Pro-Scan 1.4+, NAV
 General Comments:
       Identical to the Jerusalem virus, except that in some cases
       it does not reinfect .EXE files.  Jerusalem B is the most
       common of all PC viruses, and can infect .SYS and program
       overlay files in addition to .COM and .EXE files.

       Not all variants of the Jerusalem B virus slow down the
       system after an infection has occurred.

       Also, it should be noted that Jerusalem viruses will only activate
       if they actually become memory resident on their activation date.  If
       the system clock rolls over to the activation date and the virus is
       already memory resident, they will not typically activate and perform
       any destructive behavior they may be intended to perform.

       Known variants of Jerusalem B are:
       A-204      : Jerusalem B with the sUMsDos text string changed to
           *A-204*, and a couple of instructions changed in order to
           avoid detection.  This variant will slow down the system
           after being memory resident for 30 minutes, as well as having
           a black box appear at that time.
           Origin: Delft, The Netherlands
       Anarkia    : Jerusalem B with the timer delay set to slow
           down the system to a greater degree, though this effect
           doesn't show until a much longer time has elapsed.  No
           Black Box is never displayed.  The sUMsDos id-string has
           been changed to ANARKIA.  Lastly, the virus's activation
           date has been changed to Tuesday The 13ths, instead of
           Friday The 13ths.  Origin: Spain
       Anarkia-B  : Similar to Anarkia, with the exception that the
           virus now activates on any October 12th instead of on
           Tuesday The 13ths.
       Jerusalem-C: Jerusalem B without the timer delay to slow
           down the processor.
       Jerusalem-D: Jerusalem C which will destroy both copies of
           the FAT on any Friday The 13th after 1990.
       Jerusalem-E: Jerusalem D but the activation is in 1992.
       Mendoza    : Based on the Jerusalem B virus, this variant does
           not reinfect .EXE files.  It is also missing the black box
           effect.  Mendoza activates in the second half of the year
           (July - December), at which time any day will have a 10%
           chance of having all programs executed deleted.
           Origin: Argentina
       Park ESS: Isolated in October, 1990 in Happy Camp, California, this
           variant is very similar to other Jerusalem viruses.  Infected
           .COM files increase in length by 1,813 bytes, and infected .EXE
           files will increase in length by 1,808 to 1,822 bytes with the
           first infection, and 1,808 on later subsequent infections.  This
           variant will also infect COMMAND.COM.  The other major difference
           from the "normal" Jerusalem is that the sUMsDos string has been
           replaced.  The string PARK ESS can be found in the viral code
           within all infected files.  This variant slows down the system
           by approximately 20 percent and a "black window" will appear after
           the virus has been memory resident for 30 minutes.
       Puerto  : Isolated in June, 1990 in Puerto Rico, this variant is
           very similar to the Mendoza variant, the virus contains the
           sUMsDos id-string.  .EXE files may be infected multiple times.
       Skism-1 : Isolated in December, 1990 in New York State, this variant
           is similar to many other Jerusalems except with regards to when
           and what it does upon activation.  Rather than activate on
           Friday The 13ths and delete files, this variant activates in the
           years 1991 and later on any Friday which occurs after the 15th of
           the month.  On activation, it truncates any file which is attempted
           to be executed to zero bytes.  COM files will increase in size
           upon infection by 1,808 bytes, EXE files will increase by 1,808 to
           1,822 bytes.  EXE files will be reinfected by the virus.  The
           sUMsDos string in the virus is now SKISM-1.  Like Jerusalem, this
           variant produces a "black window" 30 minutes after becoming
           memory resident, and also slows down the system.
       Spanish JB : Similar to Jerusalem, it reinfects .EXE files.
           The increased file size on .COM files is always 1,808
           bytes.  On .EXE files, the increased file size may be
           either 1,808 or 1,813, with reinfections always adding
           1,808 bytes to the already infected file.  No "Black
           Box" appears.  The characteristic sUMsDos id-string does
           not appear in the viral code.  This variant is also sometimes
           identified as Jerusalem E2.  Origin: Spain
       Jerusalem DC: Similar to Jerusalem B, this variant has the sUMsDos
           text string changed to 00h characters.  After being memory resident
           for 30 minutes, the system will slow down by 30% and the common
           "black window" will appear on the lower left side of the screen.
           Like Jerusalem, it will infect .EXE files multiple times.  This
           variant does not carry an activation date when it will delete
           files, it appears for all intents to be "defanged".
           Origin: Washington, DC, USA
       Captain Trips: The Captain Trips variant was submitted in March, 1991,
           and is from the United States.  Its name comes from the text string
           "Captain Trips X." which occurs within the viral code.  Unlike
           most Jerusalem B variants, this variant does not display a black
           window after being memory resident for 30 minutes, nor does it
           slow down the system.  On Friday The 13th, it does not delete
           programs.  The text string "MsDos" does not occur in infected
           programs.  .COM programs will increase in size by 1,813 bytes.
           .EXE programs will increase in size by 1,808 to 1,822 bytes with
           the first infection of the file, and then by 1,808 bytes with
           subsequent infections.
       Swiss 1813 : Submitted in February, 1991, from Switzerland, this
           Jerusalem variant does not exihibit the "black window" after being
           memory resident for 30 minutes, nor does it slow down the system.
           It also does not delete programs on Friday The 13th, or any other
           Friday.  The sUMsDos text string has been changed to binary zeros.

       Also see: Jerusalem, Frere Jacques, New Jerusalem, Payday,
                 Suriv 3.00, Westwood


 Virus Name:  JoJo
 Aliases:
 V Status:    Rare
 Discovered:  May, 1990
 Symptoms:    .COM growth, system hangs
 Origin:      Israel
 Eff Length:  1,701 Bytes
 Type Code:   PRaC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V63+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+, NAV
 Removal Instructions: Scan/D, F-Prot 1.12+, Pro-Scan 2.01+
 General Comments:
       The JoJo virus was discovered in Israel in May, 1990.  The virus'
       name comes from a message within the viral code:

          "Welcome to the JOJO Virus."

       One other message appears within the virus, indicating that it was
       written in 1990.  This message is: "Fuck the system (c) - 1990".
       Both messages within the viral code are never displayed.

       When the first file infected with the JoJo Virus is executed on a
       system, the virus will install itself memory resident.  The
       method used is to alter the Command Interpreter in memory,
       expanding its size.  As an example, on my test system, the
       Command Interpreter in memory increased in size from 3,536 bytes
       to 5,504 bytes.  One block of 48 bytes is also reserved in
       available free memory.  The change in free memory will
       be a net decrease of 2,048 bytes.

       The JoJo Virus will not infect files if interrupt 13 is in use
       by any other program.  Instead the virus will clear the screen,
       and the system will be hung.  If the user performs a warm reboot
       (Ctrl-Alt-Del), the virus will remain in memory.

       Once the virus is able to become memory resident with interrupt 13
       hooked, any .COM file executed will be infected by the virus.
       Infected files will increase in length by 1,701 bytes.

       While this virus has the same length as the Cascade/1701 Virus, it
       is not a variant of Cascade.

       Also see: JoJo 2


 Virus Name:  JoJo 2
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; Message; "Not enough memory" errors; system hangs;
              cursor position off 1 character
 Origin:      United States
 Eff Length:  1,703 Bytes
 Type Code:   PRaCK - Parasitic Resident .COM Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The JoJo 2 Virus was submitted in January, 1991, by David Grant of the
       United States.  This virus is based on the JoJo Virus as well as
       containing part of the decryption string for the Cascade Virus.  It is
       a memory resident infector of .COM files, including COMMAND.COM.

       The first time a program infected with the JoJo 2 Virus is executed,
       the virus will install itself memory resident by altering the command
       interpretor in memory.  The command interpretor in memory will have a
       size increase of 1,904 bytes.  There is an additional 48 bytes which is
       reserved by the virus as well, similar to JoJo.

       Once the virus is memory resident, it will infect .COM files as they
       are executed.  If COMMAND.COM is executed for any reason, it will become
       infected.  Infected .COM programs will have a file size increase of
       1,703 bytes with the virus being located at the end of the infected
       file.

       Text strings which can be found in files infected with the JoJo 2 Virus
       are:

               "The JOJO virus strikes again.xxxxxxxxxxxx zzz"
               "Fuck the system 1990 - (c)"
               "141$FLu"

       Systems infected with the JoJo 2 virus may experience system hangs
       when some infected programs are executed.  Infected programs may also
       display the "Fuck the system 1990 - (c)" string, or a string of garbage
       characters from memory.  Attempts to execute some programs may also
       fail due to "Not enough memory" errors.  Lastly, after the virus has
       been resident for awhile, the user may notice that the cursor on the
       system monitor is off by one position to the right from where it should
       be.

       JoJo 2 may be detected by some anti-viral utilities as an infection
       of JoJo and Cascade/1701/1704.

       Also see: JoJo


 Virus Name:  Joker
 Aliases:     Jocker
 V Status:    Extinct
 Discovered:  December, 1989
 Symptoms:    Messages, .EXE/.DBF growth
 Origin:      Poland
 Eff Length:  ??? Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan, VirexPC
 Removal Instructions: Scan/D/X, or delete infected files
 General Comments:
       The Joker Virus was isolated in Poland in December, 1989.
       This virus is a generic .EXE file infector, and is a poor
       replicator (ie. it does not quickly infect other files).

       Programs which are infected with the Joker virus will
       display bogus error messages and comments.  These messages
       and comments can be found in the infected files at the
       beginning of the viral code.  Here are some of the
       messages and comments that may be displayed:

       "Incorrect DOS version"
       "Invalid Volume ID Format failure"
       "Please put a new disk into drive A:"
       "End of input file"
       "END OF WORKTIME.  TURN SYSTEM OFF!"
       "Divide Overflow"
       "Water detect in Co-processor"
       "I am hungry! Insert HAMBURGER into drive A:"
       "NO SMOKING, PLEASE!"
       " Thanks."
       "Don't beat me !!"
       "Don't drink and drive."
       "Another cup of cofee ?"
       " OH, YES!"
       "Hard Disk head has been destroyed. Can you borow me your one?"
       "Missing light magenta ribbon in printer!"
       "In case mistake, call GHOST BUSTERS"
       "Insert tractor toilet paper into printer."

       This virus may also alter .DBF files, adding messages to
       them.

       The sample in the author of this listing possession does not
       replicate on an 8088 based system.  This entry has been included
       since the sample may have been damaged before its receipt by
       the author.  At best, there is a serious bug in the replication
       portion of this virus which prevents it from replicating.


 Virus Name:  Joker 2
 Aliases:     Joker-01
 V Status:    New
 Discovered:  May, 1991
 Symptoms:    .COM & .EXE growth; TSR; System hangs
 Origin:      Unknown
 Eff Length:  29,233 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:
 Removal Instructions:  Delete infected files
 General Comments:
       The Joker 2, or Joker-01, Virus was submitted in May, 1991, by the
       PCVRF.  Its origin is unknown.  This virus is a memory resident
       infector of .COM and .EXE programs, and will not infect COMMAND.COM.

       The first time a program infected with Joker 2 is executed, Joker 2
       will install itself memory resident as a low system memory TSR of
       29,568 bytes.  Interrupts hooked by the virus include 09, 1C, and 21.

       After becoming memory resident, Joker 2 will infect .COM and .EXE files
       whose original program length was less than approximately 9K, when they
       are executed.  Programs larger than 9K are never infected.

       Infected .COM programs always increase in size by 29,233 bytes.  .EXE
       programs increase in size by 29,233 to 29,372 bytes.  In both cases the
       virus will be located at the end of the infected program.  The text
       string "JOKER-01" can be found in all infected files.

       Systems infected with Joker 2 may experience the system display being
       cleared, followed by a system hang occurring.  When this happens, a
       few spurious characters may appear on the display as well.  If Ansi.Sys
       is loaded before Joker 2 becomes resident, no screen effect will be
       produced.

       Joker 2 may be an incomplete virus, there is a large area of 00h
       characters within the virus code, implying that something else may be
       added later.


 Virus Name:  Joshi
 Aliases:     Happy Birthday Joshi, Stealth Virus
 V Status:    Common
 Discovered:  June, 1990
 Symptoms:    BSC, machine hangs and message
 Origin:      India
 Eff Length:  N/A
 Type Code:   BRX - Resident Boot Sector/Partition Table Infector
 Detection Method:  ViruScan V64+, Pro-Scan 1.4+, NAV, IBM Scan 2.00+
 Removal Instructions:  CleanUp V66+, Pro-Scan 1.4+, RmJoshi, NAV
              or Low-Level Format Harddisk and DOS SYS floppies
 General Comments:
       The Joshi Virus was isolated in India in June 1990.  At the time it was
       isolated, it was reported to be widespread in India as well as
       portions of the continent of Africa.  Joshi is a memory resident
       boot sector infector of 5.25" diskettes.  It will also infect
       hard disks, though in the case of hard disks it infects the partition
       table or master boot sector rather than the boot sector (sector 0).

       After a system has been booted from a Joshi-infected diskette, the
       virus will be resident in memory.  Joshi takes up approximately
       6K of system memory, and infected systems will show that total
       system memory is 6K less than is installed if the DOS CHKDSK program
       is run.

       Joshi has some similarities to two other boot sector infectors.
       Like the Stoned virus, it infects the partition table of hard disks.
       Similar to the Brain virus's method of redirecting all attempts to
       read the boot sector to the original boot sector, Joshi does this with
       the partition table.

       On January 5th of any year, the Joshi virus activates.  At that
       time, the virus will hang the system while displaying the message:

             "type Happy Birthday Joshi"

       If the system user then types "Happy Birthday Joshi", the system
       will again be usable.

       This virus may be recognized on infected systems by powering off
       the system and then booting from a known-clean write-protected
       DOS diskette.  Using a sector editor or viewer to look at the
       boot sector of suspect diskettes, if the first two bytes of the
       boot sector are hex EB 1F, then the disk is infected.  The EB 1F
       is a jump instruction to the rest of the viral  code. The remainder
       of the virus is stored on track 41, sectors 1 thru 5 on 360K
       5.25 inch Diskettes.  For 1.2M 5.25 inch diskettes, the viral code
       is located at track 81, sectors 1 thru 5.

       To determine if a system's hard disk is infected, you must look at
       the hard disk's partition table.  If the first two bytes of the
       partition table are EB 1F hex, then the hard disk is infected.  The
       remainder of the virus can be found at track 0, sectors 2 thru 6.
       The original partition table will be a track 0, sector 9.

       The Joshi virus can be removed from an infected system by first
       powering off the system, and then booting from a known-clean, write-
       protected master DOS diskette.  If the system has a hard disk, the
       hard disk should have data and program files backed up, and the
       disk must be low-level formatted.  As of July 15, 1990, there are
       no known utilities which can disinfect the partition table of the
       hard disk when it is infected with Joshi.  Diskettes are easier to
       remove Joshi from, the DOS SYS command can be used, or a program
       such as MDisk from McAfee Associates, though this will leave the
       viral code in an inexecutable state on track 41.


 Virus Name:  July 13TH
 Aliases:
 V Status:    Endangered
 Discovered:  April, 1990
 Symptoms:    .EXE file growth, screen effects on July 13
 Origin:      Madrid, Spain
 Eff Length:  1,201 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method:  ViruScan V64+, VirexPC, F-Prot 1.12+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, or delete infected files
 General Comments:
       The July 13TH Virus was isolated in Madrid, Spain, in April 1990
       by Guillermo Gonzalez Garcia.  This virus is a generic .EXE file
       infector, and is not memory resident.

       When a program infected with the July 13TH Virus is executed, the
       virus will attempt to infect a .EXE file.  Files are only infected
       if they are greater in length than 1,201 bytes.  Infected files
       increase in size by 1,201 to 1,209 bytes.

       The July 13TH Virus activates on July 13th of any year.  At that
       time, a bouncing ball effect occurs on the system monitor's screen
       similar to the bouncing ball effect of the Ping Pong virus.  While
       this virus is disruptive, it does not cause any overt damage to
       files other than infecting them.  The bouncing ball effect created
       by this virus will occasionally leave dots on the screen where
       it was passing if the screen has been scrolled for any reason.


 Virus Name:  June 16TH
 Aliases:     Pretoria
 V Status:    Endangered
 Discovered:  April, 1990
 Symptoms:    .COM file growth, long disk accesses, June 16th FAT alteration
 Origin:      Republic of South Africa
 Eff Length:  879 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V62+, Pro-Scan 1.4+, VirexPC, AVTK 3.5+,
              F-Prot 1.12+, VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: VirHunt 2.0+, Scan/D, Pro-Scan 2.01+, NAV
 General Comments:
       The June 16TH, or Pretoria, virus was discovered in April 1990.
       This virus is a non-resident generic .COM file infector, and is
       encrypted.  The first time an infected file is executed, the virus
       will search the current drive (all directories) and infect all
       .COM files found.  The search period can be quite long, and it is
       very obvious on hard disk based systems that the program is taking
       too long to load.

       On June 16TH of any year, the first time an infected file is
       executed the virus will activate.  On activation, the virus will
       change all entries in the root directory and the file allocation
       table to "ZAPPED".

       The June 16TH virus is thought to have originated in South
       Africa.


 Virus Name:  Kamasya
 Aliases:
 V Status:    Research
 Discovered:  March, 1991
 Symptoms:    .EXE growth; decrease in total system & available memory
 Origin:      Italy
 Eff Length:  1,098 Bytes
 Type Code:   PRE - Parasitic Resident .EXE Infector
 Detection Method: ViruScan V76+, IBM Scan 2.00+
 Removal Instructions: CleanUp V77+, or Delete infected files
 General Comments:
       The Kamasya Virus was submitted by David Grant of the United States in
       March 1991.  Mr. Grant received the virus from Italy.  The Kamasya Virus
       is based on the Murphy Virus from Bulgaria.  It is a memory resident
       infector of .EXE files.

       When a program infected with the Kamasya Virus is executed, the virus
       will check if it is already memory resident.  If it isn't already
       memory resident, it will install itself memory resident at the top
       of system memory but below the 640K DOS boundary.  A portion of the
       virus will also be in low system memory.  Interrupt 21 will be hooked
       by the virus in high system memory, and interrupt 00 in low system
       memory.  Total system and available free memory, as indicated by the
       DOS ChkDsk program, will decrease by 1,120 bytes.

       Once Kamasya is memory resident, it will infect .EXE programs over 1K
       in length when they are executed or openned for any reason.  Infected
       programs will increase in size by 1,098 bytes with the virus being
       located at the end of the infected program.  The program's date and
       time in the DOS disk directory will not be altered.

       Programs infected with Kamasya will contain the following text strings:

               "Kamasya nendriya pritir
                labho jiveta yavata
                jivasya tattva jijnasa
                nartho ya ceha karmabhih"

       It is unknown if Kamasya does anything besides replicate.

       This virus may be a research virus and not in the public domain.  The
       original sample submitted is not a natural infection of the virus.

       Also see: Murphy


 Virus Name:  Kamikazi
 Aliases:
 V Status:    Endangered
 Discovered:  August, 1990
 Symptoms:    program corruption, system hangs, system reboots
 Origin:      Bulgaria
 Eff Length:  4,031 Bytes
 Type Code:   ONE - Overwriting Non-Resident .EXE Infector
 Detection Method: Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Delete infected files
 General Comments:
       The Kamikazi Virus was submitted by Vesselin Bontchev of Bulgaria in
       August, 1990.  This virus is a non-resident overwriting virus, and
       infects .EXE files.

       When a program infected with the Kamikazi virus is executed, the virus
       will infect another .EXE file in the current directory if the .EXE
       file's length is greater than 4,031 bytes.  Kamikazi simply overwrites
       the first 4,031 bytes of the candidate program with its viral code,
       thus permanently damaging the candidate program being infected.  The
       original 4,031 bytes of code is not stored at any other location.
       Infected files do not change in length.

       After infecting another .EXE program, the virus will then change the
       first 8 bytes of the infected program that was executed to
       "kamikazi", thus the virus's name.  At this point, one of several
       symptoms may appear: the system may be rebooted by the virus, some
       of the contents of memory may get displayed on the screen, or the
       program may complete execution having appeared to have done nothing
       at all.  In any event, the original executed program will never run
       successfully, doing what the user expects.

       If the infected program is executed a second time, it will hang the
       system since it is no longer an executable program.  The .EXE header
       has been permanently damaged due to the first 8 characters having been
       changed to "kamikazi" by the virus when it was first executed.


 Virus Name:  Kemerovo
 Aliases:     USSR 257, Kemerovo-B
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM growth; ????????COM Path not found." message;
              file date/time changes
 Origin:      USSR
 Eff Length:  257 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Kemerovo Virus was submitted in December, 1990 and is from the
       USSR.  This virus is a non-resident direct action infector of .COM
       files, including COMMAND.COM.

       When a program infected with the Kemerovo Virus is executed, the virus
       will search the current drive and directory for a .COM program to
       infect.  If an uninfected COM program is found, the virus will infect
       it, adding its viral code to the end of the original program.  The
       newly infected program's date and time in the disk directory will also
       be updated to the current system date and time of infection.  Infected
       programs will increase in length by 257 bytes.

       If an uninfected .COM file was not found in the current directory, the
       message "????????COM Path not found" may be displayed and the program
       the user is attempting to execute will be terminated.

       Kemerovo does not do anything besides replicate.

       Known variant(s) of Kemerovo include:
       Kemerovo-B : Similar to Kemerovo, this variant is from the United States
               and has been altered to avoid detection by some anti-viral
               programs.  Its major distinction from the original virus is
               that it will infect five .COM programs in the current directory.

 Virus Name:  Kennedy
 Aliases:     Dead Kennedy, 333, Kennedy-333
 V Status:    Endangered
 Discovered:  April, 1990
 Symptoms:    .COM growth, message on trigger dates (see text),
              crosslinking of files, lost clusters, FAT corruption
 Origin:      Denmark
 Eff Length:  333 Bytes
 Type Code:   PNCKF - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V62+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, VirHunt 2.0+,
              or delete infected files
 General Comments:
       The Kennedy Virus was isolated in April 1990.  It is a generic
       infector of .COM files, including COMMAND.COM.

       This virus has three activation dates: June 6 (assassination of
       Robert Kennedy 1968), November 18 (death of Joseph Kennedy 1969),
       and November 22 (assassination of John F. Kennedy 1963) of any
       year. On activation, the virus will display a message the following
       message:

               "Kennedy is dead - long live 'The Dead Kennedys'"

       The following text strings can be found in the viral code:
               "\command.com"
               "The Dead Kennedys"

       Systems infected with the Kennedy Virus will experience
       crosslinking of files, lost clusters, and file allocation table
       errors (including messages that the file allocation table is
       bad).


 Virus Name:  Keypress
 Aliases:
 V Status:    Common
 Discovered:  October, 1990
 Symptoms:    .COM & .EXE growth; decrease in available free memory;
              keystrokes repeated unexpectedly
 Origin:      USA
 Eff Length:  1,232 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Clean-Up V71+, or Delete infected files
 General Comments:
       The Keypress Virus was reported and isolated in many locations in the
       United States in late October, 1990.  This virus is a memory resident
       infector of .COM and .EXE files, including COMMAND.COM.

       The first time a program infected with the Keypress Virus is executed,
       the virus will install itself memory resident at the top of free
       available memory, but below the 640K DOS boundary.  Interrupts 1C and
       21 will be hooked by the virus.  Available free memory on the system
       will have decreased by 1,232 bytes.

       After the virus is memory resident, any file executed may become
       infected by the virus.  In the case of .COM files, they are only
       infected if their original file length was greater than 1,232 bytes.
       .EXE files of any length will be infected, as will COMMAND.COM if it
       is executed.  Infected programs will have their directory date/time
       changed to the system date and time when they were infected by this
       virus.  .COM files will increase in length by between 1,234 and
       1,248 bytes upon infection.  .EXE files will increase by 1,472 to
       1,486 bytes upon infection.  In either case, the virus will be located
       at the end of the infected file.

       The Keypress Virus activates after being memory resident for 30 minutes.
       Upon activation, the virus may interfer with keyboard input by repeating
       keystrokes.  For example, if "a" is entered on the keyboard, it may be
       changed to "aaaaaa" by the virus.

       Infected files can be identified by containing the following hex string
       near the end of the infected program: 4333C98E1E2901CD21.


 Virus Name:  Korea
 Aliases:     LBC Boot
 V Status:    Common - Korea
 Discovered:  March, 1990
 Symptoms:    BSC - 360k disks
 Origin:      Seoul, Korea
 Eff Length:  N/A
 Type Code:   RF - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan V61+, VirHunt 2.0+
 Removal Instructions: CleanUp V77+, M-Disk, or DOS SYS Command
 General Comments:
       The Korea, or LBC Boot, Virus was isolated in March 1990 in
       Seoul, Korea.  This virus is a memory resident boot sector
       infector for 5.25" 360K diskettes.

       The Korea virus is not intentionally destructive, it does nothing
       in its current form except for replicating.  In some instances,
       when Korea infects a diskette it will damage the root directory as
       it moves the original boot sector to sector 11, the last sector of
       the root directory.  If sector 11 previously contained directory
       entries, they will be lost.


 Virus Name:  Lazy
 Aliases:
 V Status:    Rare
 Discovered:  February, 1991
 Symptoms:    .COM & .EXE growth; System slowdown; Slow screen writes;
              System hangs
 Origin:      Unknown
 Eff Length:  720 Bytes
 Type Code:   PRxCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V75+
 Removal Instructions: CleanUp V77+, or Delete infected files
 General Comments:
       The Lazy Virus was isolated in February, 1991, and its origin is
       unknown.  This virus is a memory resident infector of .COM files,
       including COMMAND.COM.

       The first time a program infected with the Lazy Virus is executed on
       a system, the virus will install itself memory resident in unreserved
       low system memory hooking interrupts 10 and 21.  The system processor
       will be significantly slowed down, resulting in very slow screen
       writes occurring.

       After Lazy is memory resident, it will infect .COM programs as they
       are executed.  Infected .COM programs will increase in size by 720
       bytes with the virus being located at the end of the infected file.
       The program's date and time in the disk directory will be updated to
       the current system date and time when infection occurred.  Infected
       programs can be identified by the text string "lazy" which will occur
       near the end of all infected programs.

       Systems infected with the Lazy Virus may experience unexpected system
       hangs.  These hangs occur when some programs are executed which allocate
       and overwrite the memory where the Lazy Virus resides in memory.  For
       example, ViruScan will hang when it checks memory if Lazy is currently
       resident.


 Virus Name:  Lehigh
 Aliases:     Lehigh University
 V Status:    Rare
 Discovered:  November, 1987
 Symptoms:    Corrupts boot sector & FAT
 Origin:      Pennsylvania, USA
 Eff Length:  N/A
 Type Code:   ORaKT - Overwriting Resident COMMAND.COM Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions: MDisk & replace COMMAND.COM with clean copy, or
       F-Prot, NAV
 General Comments:
       The Lehigh virus infects only the COMMAND.COM file on both
       floppies and hard drives.  The infection mechanism is to over-
       write the stack space.  When a disk which contains an
       uninfected copy of COMMAND.COM is accessed, that disk is then
       infected.  A infection count is kept in each copy of the virus,
       and after 4 infections, the virus overwrites the boot sector and
       FATs.

       A variation of the Lehigh virus, Lehigh-2, exists which
       maintains its infection counter in RAM and corrupts the boot
       sector and FATs after 10 infections.

       Known variants of the Lehigh virus are:
       Lehigh-2 : Similar to Lehigh, but the infection counter is maintained
                  in RAM, and the corruption of the boot sector and FATs
                  occurs after 10 infections.
       Lehigh-B : Similar to Lehigh, the virus has been modified to
                  avoid detection.


 Virus Name:  Leprosy
 Aliases:     Leprosy 1.00, News Flash
 V Status:    Rare
 Discovered:  August, 1990
 Symptoms:    unusual messages; program corruption
 Origin:      California, USA
 Eff Length:  666 Bytes
 Type Code:   ONAK - Overwriting Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D/X, or Delete infected files
 General Comments:
       The Leprosy Virus was discovered in the San Francisco Bay Area of
       California on August 1, 1990.  This virus is a non-resident
       overwriting virus infecting .COM and .EXE files, including
       COMMAND.COM.  Its original carrier file is suspected to be a file
       called 486COMP.ZIP which was uploaded to several BBSes.

       When you execute a program infected with the Leprosy virus, the virus
       will overwrite the first 666 bytes of all .COM and .EXE files in
       the directory one level up from the current directory.  If the
       current directory is the root directory, all programs in the root
       directory will be infected.  If COMMAND.COM is located in the directory
       being infected, it will also be overwritten.  Infected files will show
       no file length increase unless they were originally less than 666
       bytes in length, in which case their length will become 666 bytes.

       After the virus has infected the .COM and .EXE files, it will display
       a message.  The message will be either:

               "Program to big to fit in memory"

       or:

               "NEWS FLASH!!  Your system has been infected with the
                incurable decay of LEPROSY 1.00, a virus invented by
                PCM2 in June of 1990.  Good luck!"

       The second message will only be displayed by one out of every seven
       .COM and .EXE files that the program infects.

       Since Leprosy is an overwriting virus, the programs which are
       infected with it will not function properly.  In fact, once they are
       infected with this virus they will run for awhile (while the virus is
       infecting other files) and then display one of the two messages.  The
       program execution will then end.

       If the system is booted from a diskette or hard drive that has Leprosy
       in its COMMAND.COM file, one of the above two messages will be
       displayed followed by:

               "Bad or missing Command Interpreter"

       This boot problem occurs because COMMAND.COM is no longer really
       COMMAND.COM.  The boot will not proceed until a system boot diskette
       is inserted into the system and another boot is attempted.

       While Leprosy's messages are encrypted in the virus, infected files
       can be found by checking for the following hex string near the
       beginning of the file:

               740AE8510046FE06F002EB08

       Infected files must be deleted and replaced with clean, uninfected
       copies.  There is no way to disinfect this virus since the first 666
       bytes of the file have been overwritten, the virus does not store
       those bytes anywhere else.

       Known variant(s) of the Leprosy virus are:
       Leprosy-B : The major differences between the Leprosy and Leprosy-B
               virus are that Leprosy-B uses a slightly different encryption
               method, thus allowing it to avoid detection once Leprosy was
               isolated.  Additionally, instead of infecting all programs in
               the directory selected for infection, Leprosy-B will infect
               four programs in the current directory each time an infected
               program is executed.  If four non-infected files do not exist
               in the current directory, it will move up one level in the
               directory structure and infect up to four files in that
               directory.  Like Leprosy, it overwrites the first 666 bytes
               of infected files.  The Leprosy message has been replaced
               with the following message:

               "ATTENTION!  Your computer has been afflicted with
                the incurable decay that is the fate wrought by
                Leprosy Strain B, a virus employing Cybernetic
                Mutation Technology (tm) and invented by PCM2  08/90."


 Virus Name:  Liberty
 Aliases:
 V Status:    Common
 Discovered:  May, 1990
 Symptoms:    .COM, .EXE, .OVL growth
 Origin:      Sydney, Australia
 Eff Length:  2,862 Bytes
 Type Code:   PRfAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V63+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: VirHunt 2.0+, Clean-Up V72+, or Delete infected files
 General Comments:
       The Liberty Virus was isolated in Sydney, Australia in May, 1990.
       Liberty is a memory resident generic file infector, infecting
       .COM, .EXE, and overlay files.  COMMAND.COM may also become
       infected.

       The Liberty Virus gets its name from the text string "Liberty"
       which will appear in all infected files.  In .EXE files, it will
       be located in the last 3K of the file.  In .COM files, it will
       appear near the very beginning of the program, as well as within the
       last 3K of the infected file.

       The first time a file infected with the Liberty Virus is executed,
       the virus will become memory resident.  Liberty installs itself
       resident in high free memory, resulting in a decrease of 8,496 bytes
       of available free memory.  It also directly changes the interrupt
       map page in memory so that interrupts 21 and 24 will put the virus in
       control.  Total system memory does not change.

       After becoming memory resident, programs which are executed may
       be infected by the virus.  All .EXE files will be infected, but
       only .COM files over 2K in length will become infected.  Overlay
       files will also become infected.  Infected files will increase
       in size between 2,862 and 2,887 bytes, and will end with the hex
       character string: 80722D80FA81772880.  The main body of the virus will
       be located at the end of all infected files.

       Infected .COM files can also be identified by the following text
       string which will appear near the beginning of the infected program:

               "- M Y S T I C - COPYRIGHT (C) 1989-2000, by SsAsMsUsEsL"

       This string does not appear in infected .EXE files, the area where
       this string would have appeared in infected .EXE files will be 00h
       characters.

       Liberty is a self-encrypting virus.  It is not yet known if it
       is destructive.

       Known variant(s) of Liberty are:
       Liberty-B : Isolated in November, 1990, this strain is functionally
               similar to the original Liberty Virus.  The string which
               occurs at the end of all infected files has been changed
               to: C8004C40464842020EB.  The word "MAGIC" will also be found
               repeated together many times in infected files.
       Liberty-C : Isolated in January, 1991, this variant is very similar to
               Liberty-B, there are 16 bytes which have been changed.  Like
               Liberty-B, the word "MAGIC" will be found repeated together
               many times in infected files.  The string which occurs at the
               end of all infected files has been changed to:
               C8004C404648422020E9.


 Virus Name:  Lisbon
 Aliases:
 V Status:    Rare
 Discovered:  November, 1989
 Symptoms:    .COM growth, Unusable files (see text)
 Origin:      Lisbon, Portugal
 Eff Length:  648 bytes
 Type Code:   PNCK - Parasitic Non-Resident COM Infector
 Detection Method:  ViruScan V49+, F-Prot, IBM Scan, Pro-Scan, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions: CleanUp, Pro-Scan 1.4+, VirexPC, F-Prot, VirHunt 2.0+,
              NAV
 General Comments:
       The Lisbon virus is a strain of the Vienna virus first
       isolated by Jean Luz in Portugal in November, 1989.  The virus
       is very similar to Vienna, except that almost every word in
       the virus has been shifted 1-2 bytes in order to avoid virus
       identification/detection programs which could identify the
       Vienna virus.

       When a program infected with Lisbon is executed, the virus will infect
       or corrupt one .COM file in the current directory.  If a program is
       infected, 648 bytes will be added to the programs length with the virus
       being located at the end of the program.  These programs will have
       the text strings below near the end of the infected program:

               "@AIDS"
               "????????COM"

       If a program was corrupted instead of being infected, the first five
       characters of the program will be "@AIDS".  These corrupted programs
       will no longer execute properly, usually resulting in a system hang
       when when they are executed.  Corrupted files will not have any file
       length increase since the first five characters were overwritten by
       the "@AIDS" string.

       Known variant(s) of Lisbon include:
       Lisbon-B  : Similar to Lisbon, this variant does not contain the
                   "@AIDS" string.  It also may hang the system when it
                   attempts to infect .COM files.  Programs corrupted by this
                   variant will be begin with the hex string "FEB8140C50", and
                   programs infected with the actual Lisbon-B variant will end
                   with this string.
       Lisbon-B2 : Lisbon-B2 is a very minor variant of Lisbon-B, differing
                   by 2 bytes.  Otherwise, it is functionally identical.

       Also see: Vienna


 Virus Name:  Little Pieces
 Aliases:     1374
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM & .EXE growth; decrease in available free memory; message;
              system hangs; unexpected screen clears
 Origin:      Italy
 Eff Length:  1,374 Bytes
 Type Code:   PRaE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected programs
 General Comments:
       The Little Pieces Virus was isolated in January, 1991, in Italy.  This
       virus is a 1,374 byte memory resident infector of .EXE files.

       The first time a program infected with Little Pieces is executed, the
       virus will install itself memory resident.  The area where it is memory
       resident is 1,392 bytes long and labelled COMMAND Data in low system
       memory.  Some memory mapping utilities will combine this area with the
       command interpretor, so the command interpretor will appear to be 1,392
       bytes longer than expected.  Interrupts 13, 16, and 21 are hooked by
       the Little Pieces Virus.

       Once Little Pieces is memory resident, it will infect .EXE programs
       as they are executed.  Infected .EXE programs will increase in size by
       1,374 bytes and have the virus located at the end of the infected
       file.  Infected files will not have their date and time in the disk
       directory altered.

       Systems infected with the Little Pieces Virus may experience the system
       display being cleared unexpectedly after a key is pressed on the
       keyboard.  The following message is usually displayed after the
       screen is cleared, though not always:

               "One of these days I'm going to cut you into little pieces"

       This message cannot be viewed in infected files as it is encrypted
       within the virus.

       Infected system may also experience unexpected system hangs occurring,
       requiring the system to be rebooted.  These hangs sometimes occur after
       the above message is displayed.


 Virus Name:  Lozinsky
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth; file date/time changes;
              decrease in total system and available free memory
 Origin:      USSR
 Eff Length:  1,023 Bytes
 Type Code:   PRtCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected programs
 General Comments:
       The Lozinsky Virus was submitted in December, 1990 from the USSR.
       Lozinsky is a memory resident infector of .COM files, including
       COMMAND.COM.

       When the first program infected with Lozinsky is executed, the virus
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  Interrupt 12's return will be moved so
       that the system will report 2,048 bytes of memory less than what is
       actually installed.  Interrupts 13 and 21 will be hooked by the virus.
       COMMAND.COM will also become infected at this time.

       After Lozinsky is memory resident, it will infect .COM files which are
       executed or openned for any reason.  Infected programs will show a file
       length increase of 1,023 bytes and have the virus located at the end
       of the program.  Their date and time in the disk directory will also
       have been updated to the system date and time when the program was
       infected by Lozinsky.

       It is unknown if Lozinsky does anything besides replicate.


 Virus Name:  M.I.R.
 Aliases:     MIR
 V Status:    New
 Discovered:  May, 1991
 Symptoms:    .COM & .EXE growth; BSC; .SYS file corruption;
              Decrease in total system & available memory; Boot failures;
              Garbling of system date/time display
 Origin:      Europe
 Eff Length:  1,745 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method: IBM Scan 2.00+
 Removal Instructions: Delete infected files & DOS Sys Disk
 General Comments:
       The M.I.R. Virus was submitted in May 1991 by the PCVRF.  It is
       originally from Europe.  This virus is a memory resident infector of
       .COM and .EXE programs, including COMMAND.COM.  It also modifies
       diskette boot sectors and .SYS files, though the virus cannot replicate
       from these areas.

       The first time a program infected with M.I.R. is executed, the virus
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  Interrupts 21 and 27 will be hooked by
       the virus.  Total system and available free memory, as indicated by
       the DOS ChkDsk program, will be 3,584 bytes less than is expected.  At
       this time, the boot sector of diskettes will be modified, though the
       modification does not result in an infectious copy of the virus.

       Once M.I.R. is memory resident, it will infect .COM and .EXE files
       which are at least 2K in length when they are executed.  Infected .COM
       programs will have a length increase of 1,745 bytes, while .EXE
       programs will increase in size by 1,745 to 1,759 bytes.  In both
       cases, the virus will be located at the end of the infected file.
       M.I.R. does not hide the file length increase, nor does it alter the
       program's date and time in the DOS disk directory.

       One text string can be found in infected programs, located near the
       beginning of the viral code:

               "#.I.R. *-*-*-* Sign of the time!"

       As an M.I.R. infection progresses, the system file MSDOS.SYS may become
       infected by the virus.  This file does not contain an infectious copy
       of the virus, but is damaged.  Attempts to boot from disks with a
       M.I.R. modified boot sector and MSDOS.SYS, as well as an infected
       COMMAND.COM will result in a garbled system date and time, followed
       by the system hanging.

       It is unknown if M.I.R. does anything besides replicate.


 Virus Name:  Mardi Bros
 Aliases:
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    BSC; volume label change; decrease in system and free memory
 Origin:      France
 Eff Length:  N/A
 Type Code:   FR - Floppy Boot Sector Infector
 Detection Method:  ViruScan V66+
 Removal Instructions: CleanUp V77+, M-Disk, or DOS SYS Command
 General Comments:
       The Mardi Bros Virus was isolated in July 1990 in France.  This virus
       is a memory resident infector of floppy disk boot sectors.  It does
       not infect hard disk boot sectors or partition tables.

       When a system is booted from a diskette infected with the Mardi Bros
       Virus, the virus will install itself memory resident.  It resides in
       7,168 bytes above the top of memory, but below the 640K DOS Boundary.
       The decrease in system and free memory can be seen using the DOS
       CHKDSK command, or several other memory mapping utilities.

       Mardi Bros will infect any non-write protected diskette which is
       exposed to the system.  Infected diskettes can be easily identified
       as their volume label will be changed to "Mardi Bros".  The CHKDSK
       program will show the following for the diskette's Volume label
       information:

            "Volume Mardi Bros created ira 0, 1980 12:00a"

       While the infected boot sector on the diskette will have the DOS
       messages still remaining, it will also include the following phrase
       near the end:

            "Sudah ada vaksin"

       It is unknown if Mardi Bros is destructive, it appears to do nothing
       but spread.

       Mardi Bros can be removed from infected diskettes by first powering
       off the system and rebooting from a known clean write protected
       DOS master diskette.  The DOS SYS command should then be used to
       replace the infected diskette's boot sector.  Alternately, MDisk
       can be used following the power-down and reboot.


 Virus Name:  MG
 Aliases:
 V Status:    Rare
 Discovered:  September, 1990
 Symptoms:    .COM file growth; DIR command may not function properly;
              File allocation errors; System hangs
 Origin:      Bulgaria
 Eff Length:  500 Bytes
 Type Code:   PRCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The MG Virus was submitted in January, 1991, though it has been
       mentioned by Bulgarian researchers several times since September, 1990.
       This virus is named MG as it was originally isolated at
       Matematicheska Gimnazia, a school in Varna, Bulgaria.  It is a memory
       resident infector of .COM files, including COMMAND.COM.

       The first time a program infected with MG is executed, the virus will
       install itself memory resident in a portion of the interrupt table in
       memory.  Interrupt 24 is hooked by the virus, as are several other
       interrupts.

       After MG is memory resident, it will infect programs when one of two
       things occurs: either the user attempts to execute any program, or a
       Dir command is performed.  In the case of a program being executed, the
       virus will infect one program in the current directory, though not
       necessarily the program being executed.  When a Dir command is executed,
       one program in the current directory will be infected as well.

       .COM programs infected with MG will increase in length by 500 bytes,
       though the file length increase will not be visible in a dir listing
       if the virus is memory resident.  File date and time in the disk
       directory are also not altered.  The virus will be located at the end
       of infected programs.

       Symptoms of a MG infection are that the DOS Chkdsk program will show
       File allocation errors on all infected .COM programs if the virus is
       present in memory.  The DOS Dir command may also not function properly,
       for example DIR A:*.COM will yield "File not found" even though .COM
       files exist on the A: drive.  At other times, pauses will occur in the
       disk directory being displayed by the Dir command.  Another symptom is
       that unexpected system hangs may occur due to the interrupt table being
       infected in memory.

       Also see: MG-2


 Virus Name:  MG-2
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth; File Allocation Errors;
              Dir command may not function properly
 Origin:      Bulgaria
 Eff Length:  500 Bytes
 Type Code:   PRsCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The MG-2 Virus was received in December, 1990, and is believed to have
       originated in Bulgaria.  This virus is a direct action, memory resident
       infector of .COM programs, including COMMAND.COM.

       When a program infected with the MG-2 Virus is first executed, the
       virus will install itself memory resident.  The DOS ChkDsk command,
       when executed on an infected system, will indicate that total system
       memory and available free memory have decreased by 55,104 bytes.  This
       virus remaps many interrupts, including interrupt 24.  A portion of the
       virus will also be resident above 640K if memory is available.

       After the MG-2 Virus is memory resident, it will infect one .COM
       program in the current directory each time an infected .COM program is
       executed.  Infected .COM programs will not show a file length increase
       if the virus is memory resident.  With the virus memory resident, the
       DOS ChkDsk command will indicate a file allocation error for all
       infected files.  Infected files actually increase 500 bytes in length
       and have the virus located at the end of the infected file.

       Systems infected with the MG-2 Virus may notice that the DOS Dir
       command does not always return the results expected.  For example,
       issuing a "DIR C:\DOS" command may result in the C: drive root directory
       being displayed instead of the C:\DOS directory. Another case is that
       issuing the command "DIR A:*.COM" will result in "File not found" though
       .COM files exist on that drive.

       Known variant(s) of MG-2 are:
       MG-3    : Functionally similar to MG-2, this variant has been altered
                 to avoid detection.  It is also 500 bytes in length.

       Also see: MG


 Virus Name:  MGTU
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth; excessive disk activity; file date/time changes;
              "????????COM Path not found." message
 Origin:      USSR
 Eff Length:  273 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The MGTU Virus was submitted in December, 1990 and came from the USSR.
       This virus is a non-resident direct action infector of .COM files,
       including COMMAND.COM.

       When a program infected with the MGTU Virus is executed, the virus will
       search the current drive and directory for uninfected .COM programs.
       All uninfected .COM programs will become infected with the virus.
       Infected .COM programs will have a file length increase of 273 bytes
       with the virus being located at the end of the file.  Their date and
       time in the disk directory will also have been updated to the system
       date and time when infection occurred.

       Infected systems will display excessive disk activity each time an
       infected program is executed.  This activity occurs because the virus
       is checking all of the .COM programs in the current directory to
       determine if they are already infected, or if they need to be infected.
       Infected systems may also experience the following message being
       displayed for no apparent reason:

               "????????COM Path not found."

        MGTU does not do anything besides replicate.


 Virus Name:  Microbes
 Aliases:
 V Status:    Common - India
 Discovered:  June, 1990
 Symptoms:    BSR
 Origin:      Bombay, India
 Eff Length:  N/A
 Type Code:   BR - Floppy and Hard Disk Boot Sector Infector
 Detection Method:  ViruScan V64+, Pro-Scan 1.4+
 Removal Instructions: M-Disk, Pro-Scan 1.4+, or DOS SYS Command
 General Comments:
       The Microbes virus was isolated in June, 1990 in India.  It is a
       memory resident boot sector infector of both floppy diskettes and
       hard disks.

       The Microbes virus becomes memory resident when a system is booted
       from a disk infected with the Microbes virus.  The system may hang
       on this boot, and inserted a diskette to boot from will result in
       this new diskette becoming infected.  At least on the author's XT
       test system, the system could not successfully boot with the
       Microbes virus present without powering off the system and rebooting
       from a write protected master boot diskette.

       As with other boot sector infectors, Microbes can be disinfected
       from diskettes and hard drives by powering off the system and
       booting from a known clean write protected master boot diskette
       for the system.  The DOS SYS command can then be used to recreate
       the boot sector on the diskette.


 Virus Name:  Migram
 Aliases:
 V Status:    Research
 Discovered:  March, 1991
 Symptoms:    .EXE growth; decrease in total system & available free memory
 Origin:      Italy
 Eff Length:  1,221 Bytes
 Type Code:   PRhE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan V76+, IBM Scan 2.00+
 Removal Instructions: CleanUp V77+, Scan/D, or Delete infected files
 General Comments:
       The Migram Virus was submitted in March, 1991, by David Grant of the
       United States, whom received the virus from Italy.  This virus is a
       memory resident infector of .EXE files and is based on the Murphy Virus
       from Bulgaria.

       When a program infected with the Migram Virus is executed, the virus
       will check to see if it is already memory resident.  If the virus is
       not resident, the virus will install itself resident at the top of
       system memory, but below the 640K DOS boundary.  The interrupt 12
       return is not moved.  Interrupt 21 is hooked by the virus.  Total
       system memory and available free memory, as indicated by the DOS ChkDsk
       program, will decrease by 1,248 bytes.

       Once Migram is memory resident, it will infect .EXE files over 1K in
       length when they are executed or openned for any reason.  Infected
       programs will increase in length by 1,221 bytes with the virus being
       located at the end of the infected file.  The file's date and time in
       the disk directory will not be altered.

       Programs infected with Migram will contain the following text strings:

               "MIGRAM VIRUS 1.0
                (C) 1991 IVL"

       It is unknown what Migram does besides replicate.

       The original sample of this virus is not a natural infection of the
       virus, so it is possible this virus is a research virus and not in the
       public domain as of March, 1991.

       Also see: Murphy, Smack


 Virus Name:  Mini-45
 Aliases:
 V Status:    New
 Discovered:  April, 1991
 Symptoms:    .COM file corruption; File date/time changes
 Origin:      Unknown
 Eff Length:  45 Bytes
 Type Code:   ONCK - Overwriting Non-Resident .COM Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The Mini-45 Virus was received in April, 1991.  Its origin is
       unknown.  This virus is a non-resident overwriting virus which infects
       .COM files, including COMMAND.COM.

       When a program infected with Mini-45 is executed, the virus will
       infect all .COM programs in the current directory by overwriting the
       first 45 bytes of the program with the viral code.  No file size
       increase will be noticed, unless the original program was less than
       45 bytes in length, in which case it will now be 45 bytes in length.
       The .COM programs' date and time in the disk directory will be updated
       to the current system date and time of infection.

       All .COM programs infected with Mini-45 will fail to function
       properly after infection.  These programs will be permanently damaged
       since the first 45 bytes are lost.


 Virus Name:  Mirror
 Aliases:
 V Status:    Rare
 Discovered:  October, 1990
 Symptoms:    .EXE growth; decrease in available free memory; mirror effect
              of display on activation
 Origin:      Unknown
 Eff Length:  927 Bytes
 Type Code:   PRhE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Mirror Virus was discovered in October, 1990.  This virus is a
       memory resident direct action infector of .EXE files.

       The first time a program infected with the Mirror Virus is executed,
       the virus will install itself memory resident at the top of free
       available memory.  Free available memory will decrease by 928 bytes,
       and the virus will hook interrupt 21.  At this time, the virus will
       also infect all other .EXE programs located in the current directory.
       Infected programs will increase in length by 927 to 940 bytes, with
       the virus being located at the end of the infected file.  Infected
       programs will also always end with the two text characters "IH".

       The Mirror Virus gets its name from its behavior.  Every once in awhile
       it will change the system's video display so that a mirror image of
       what was previously on the display appears.


 Virus Name:  MIX/1
 Aliases:     MIX1, Mix1
 V Status:    Rare
 Discovered:  August, 1989
 Symptoms:    TSR, .EXE growth, location 0:33C = 77h, garbled output
 Origin:      Israel
 Eff Length:  1,618 Bytes
 Type Code:   PRsE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan V37+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D, Virus Buster, Pro-Scan 1.4+, VirexPC 1.1B+,
              F-Prot, VirHunt 2.0+
 General Comments:
       The MIX1 Virus was originally isolated on August 22, 1989, on
       several BBSs in Israel.  This virus is a parasitic memory-
       resident .EXE file infector.  Once an infected program has been
       executed, the virus will take up 2,048 bytes in RAM.  Each
       .EXE file then executed will grow in length between 1,618 and
       1,634 bytes, depending on the original file size.  The virus
       will not, however, infect files of less than 8K in size.

       Infected files can be manually identified by a characteristic
       "MIX1" always being the last 4 bytes of an infected file.
       Using Debug, if byte 0:33C equals 77h, then the MIX1 virus is
       in memory.

       This virus will cause garbled output on both serial and
       parallel devices, as well as the num-lock being constantly
       on.  After the 6th infection, booting the system will crash
       the system due to a bug in the code, and a ball will start
       bouncing on the system monitor.

       There is a variant of this virus which does not have the
       problem of system crashes occurring, and will only infect files
       that are greater than 16K in length.

       Mix/1 has several code similarities to Icelandic, which it may
       have been derived from.

       Also see: Icelandic, Mix2


 Virus Name:  Mix2
 Aliases:
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM & .EXE growth; system hangs;
              Decrease in total system and available free memory
 Origin:      Europe
 Eff Length:  2,287 Bytes
 Type Code:   PRhA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V76+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Mix2 Virus was submitted in March, 1991.  Original reports of this
       virus were received from Europe.  Mix2 is based on the Mix1 virus, and
       is a memory resident infector of .COM and .EXE files.  It does not
       infect COMMAND.COM

       When the first program infected with Mix2 is executed, Mix2 will install
       itself memory resident at the top of system memory, but below the 640K
       DOS boundary.  It will mark this area of reserved memory "COMMAND Data"
       and will hook interrupt 21.  Total system and available free memory, as
       indicated by the DOS ChkDsk program, will decrease by 3,040 bytes.
       Interrupt 12's return will not be moved.

       Once Mix2 is memory resident, it will infect .COM and .EXE programs over
       9K in length when they are executed.  Infected programs will increase
       in length by 2,287 to 2,294 bytes with the virus being located at the
       end of the infected file.  This virus does not alter the file date and
       time in the disk directory.

       Some programs which are memory intensive, or which allocate all
       available memory will hang when executed with Mix2 memory resident.

       It is unknown what Mix2 does besides replicate.

       Also see: Mix1


 Virus Name:  Monxla
 Aliases:     Time Virus
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    .COM growth; system hangs and/or reboots; program execution
              failures
 Origin:      Hungary
 Eff Length:  939 Bytes
 Type Code:   PRfCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V71+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Monxla, or Time, Virus was discovered in November, 1990 in Hungary.
       This virus is a memory resident direct action infector of .COM files,
       including COMMAND.COM.

       When a program infected with the Monxla Virus is executed, the virus
       will check the current system time.  If the system time's current
       seconds is greater than 32/100's of a second, the virus will install
       a very small portion of itself memory resident at the top of free
       memory but below the 640K DOS boundary.  The virus allocates 80 bytes,
       and will hook interrupts 20 and F2.  The F2 interrupt is later used to
       determine if the virus is in memory, thus avoiding multiple memory
       allocations.  The memory resident portion of the virus is not used to
       infect files.

       Each time a program infected with the Monxla Virus is executed, the
       virus will search for one uninfected .COM file with a length between
       3,840 and 64,000 bytes to infect.  The current directory is searched
       first, and then the directories along the system path.  Once an
       uninfected .COM file is found that satisfies the length requirement,
       the virus will infect it.  On other than the 13th day of any month,
       the virus will add its viral code to the end of the candidate file,
       increasing the file's length by 939 bytes.

       On the 13th day of any month, the virus activates.  The activation
       involves damaging the files that it infects based on the current
       seconds in the system time.  At the time the virus attempts to infect
       another .COM file, the virus will damage the file in one of three
       ways.  If the current seconds was greater than 60/100's, 4 HLTs followed
       by a random interrupt will be placed at the beginning of the file
       being infected.  Later when the program is executed, it may perform
       rather strangely be destructive.  It depends on what the random interrupt
       was.  If the current seconds was greater than 30/100's, but less than
       60/100's, two INT 19 calls are placed at the beginning of the file.
       Later when the program is executed, it will attempt to perform a warm
       reboot preserving the current interrupt vectors.  This, however, will
       result in a system hang if any interrupt between 00h and 1Ch was
       previously hooked.  If the current seconds was greater than 00/100's
       but less than 30/100's, a INT 20 call is placed at the beginning of
       the program being infected, thus resulting in it immediately terminating
       when later executed.


 Virus Name:  Monxla B
 Aliases:     Time B, Vienna 535
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; File corruption
 Origin:      Hungary
 Eff Length:  535 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Monxla B Virus was isolated in January, 1991 in Hungary.  This virus
       is a non-resident direct action infector of .COM files, including
       COMMAND.COM.

       When a program infected with Monxla B is executed, the virus will check
       the seconds portion of the system time.  Depending on the value found,
       either one .COM program in the current directory will be infected, or
       one .COM program in the current directory will be corrupted.

       If the seconds portion of the system time is equal 0 or a multiple of 8,
       one .COM program in the current directory, or on the system path, will
       be corrupted by the first five characters of the selected .COM program
       being changed to the hex string: 004D004F4D, or " M OM" in text.
       Corrupted programs will not have a file length increase.  Later
       execution of these corrupted programs will usually result in the
       system being hung, requiring a reboot.

       If the seconds portion of the system time was not 0 or a multiple of 8,
       a .COM program in the current directory will be infected with Monxla B.
       If no programs exist in the current directory which are neither
       corrupted or infected, the virus will follow the system path to find a
       candidate program to infect.

       Infected .COM programs will increase in length by 535 bytes, the virus
       will be located at the end of infected programs.  The virus will also
       have changed the seconds in the file time in the disk directory to 58
       so that the virus can later tell that the file is infected.


 Virus Name:  Murphy
 Aliases:     Murphy-1, V1277, Stealth Virus
 V Status:    Common - Bulgaria
 Discovered:  April, 1990
 Symptoms:    .COM & .EXE growth, system hangs, speaker noise,
              possible bouncing ball effect (see Murphy-2 below)
 Origin:      Sofia, Bulgaria
 Eff Length:  1,277 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V63+, Pro-Scan 1.4+, F-Prot 1.12+, NAV
 Removal Instructions:  CleanUp V77+, Pro-Scan 1.4+, NAV, or
              Delete infected files
 General Comments:
       The Murphy Virus was isolated in Bulgaria in April, 1990.  It is
       a memory resident generic .COM & .EXE infector, and will infect
       COMMAND.COM.

       The first time an infected program is executed on a system, the
       virus installs itself memory resident.  After it is memory resident,
       if a file is executed, or openned for any reason, it is infected by
       the Murphy Virus.  When the first non-infected program is executed
       with the virus in memory, the virus will attempt to infect
       COMMAND.COM.  The program being executed will also be infected at
       that time.  Infected programs will increase in length by
       1,277 Bytes.  Programs which are less than 1,277 Bytes in length
       will not be infected.

       The Murphy Virus watches the system time.  When the system time is
       between 10AM and 11AM, the virus will turn on the system speaker
       and send a 61h to it.  At any other time, the virus will not
       attempt to use the system speaker.

       The following text message is contained within the Murphy Virus,
       giving an idea of when it was written and by whom, though they are
       not displayed:

            "Hello, I'm Murphy.  Nice to meet you friend.
             I'm written since Nov/Dec.
             Copywrite (c)1989 by Lubo & Ian, Sofia, USM Laboratory."

       Systems infected by the Murphy Virus may also experience system
       hangs when the virus attempts to infect .EXE files.

       Known variant(s) of the Murphy Virus are:
       Murphy-2 or V1521: Similar to the Murphy Virus, its length is 1,521
              Bytes.  The non-displayed messages in the virus are now:

             "It's me - Murphy.
              Copywrite (c)1990 by Lubo & Ian, Sofia, USM Laboratory."

              The Murphy-2 will infect any .EXE file, as well as any .COM
              file over 900 Bytes.  Instead of turning the system speaker
              on between 10AM and 11AM, this variant waits for the system
              time to have the minutes set to 00, then it may have a
              "bouncing ball" effect similar to several other viruses.
              This effect does not, however, occur on all systems.
       Swami: The Swami Virus was submitted in May, 1991, from a United States
              source.  Its origin is unknown.  It is a variant of Murphy and
              will be detected as Murphy by some anti-viral utilities.  Unlike
              Murphy, this variant does not infect COMMAND.COM.  Swami
              infected files will have a file length increase of 1,250 bytes.
              It will infect programs when they are executed, openned, or
              copied.  Infected files will contain the following text string:

                  "Bhaktivedanta Swami Prabhupada (1896 - 1977)"

              Swami activates on April 15, when it will delete the first .EXE
              file in the current directory when the virus becomes memory
              resident.

       Also see: AntiChrist, HIV, Kamasya, Migram


 Virus Name:  MusicBug
 Aliases:     Music Boot, Music Bug
 V Status:    Common
 Discovered:  December, 1990
 Symptoms:    decrease in total system and available free memory; clicking;
              music randomly played on system speaker; lost clusters
 Origin:      Taiwan
 Eff Length:  N/A
 Type Code:   BRtX - Resident Boot Sector & Partition Table Infector
 Detection Method:  ViruScan V72+
 Removal Instructions:  Clean-Up V74+, or see below
 General Comments:
       The MusicBug Virus is a memory resident boot sector and partition table
       infector discovered in December, 1990.  It originated in Taiwan.

       When a system is booted from a diskette infected with the MusicBug
       Virus, the virus will install itself memory resident at the top of
       system memory but below the 640K DOS boundary.  The interrupt 12 return
       will be moved, so 640K systems will now report 638K of installed
       system memory.  Clicking may be heard for a short time from the system
       speaker before the boot proceeds, but more likely a section of a tune
       will be played.  The boot will then proceed.

       Once MusicBug is memory resident, it will periodically play another
       portion of the same tune when disk accesses occur.  It is thus rather
       disruptive.

       When MusicBug is memory resident, any disk accessed (including the
       system hard disk) will become infected with the virus.  In the case
       of hard disks, MusicBug infects the hard disk partition table and boot
       sector.

       Infected disks will have 4K in lost clusters which will contain the
       virus's code as well as a copy of the disk's original boot sector.
       The following text strings can also be found in these lost clusters:

               "MusicBug v1.06. MacroSoft Corp."
               "Made in Taiwan"

        Diskettes infected with the MusicBug Virus can be disinfected after
        powering off the system and booting from a write protected system
        diskette, then using the DOS SYS command.  The lost clusters can then
        be removed by using the ChkDsk command with the /F parameter.

        Hard disks, however, cannot be disinfected in the same way.  While
        the DOS SYS command will remove the virus from the hard disk's boot
        sector, and the lost clusters can be recovered, the hard disk will
        remain an unbootable non-system disk until a low-level format is
        performed.


 Virus Name:  Naughty Hacker Family
 Aliases:     Naughty Hacker, Horse, Stealth
 V Status:    New
 Discovered:  April, 1991
 Symptoms:    .COM & .EXE growth; Decrease in total system & available memory;
              File allocation errors; Buzzing from system speaker & clicking
 Origin:      Sofia, Bulgaria
 Eff Length:  1,154 or 1,160 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:
 Removal Instructions:  Delete infected files
 General Comments:
       The Naughty Hacker Family is a group of four viruses which were
       submitted in April 1991.  The viruses in this family are all stealth-
       type viruses, and functionally are very similar.  Two of the viruses
       are 1,154 bytes in length, while the other two viruses are 1,160 bytes
       in length.

       When a program infected with one of the Naughty Hacker Family is
       executed, the virus will install itself memory resident at the top
       of system memory but below the 640K DOS boundary.  Interrupts 01 and
       21 will be hooked by the virus.  Total system and available free
       memory, as measured with the DOS ChkDsk program, will decrease by
       1,280 bytes.  At this time, the virus will also infect COMMAND.COM
       if it hasn't previously been infected.

       After a Naughty Hacker Family virus is memory resident, it will infect
       .COM and .EXE files over 1K in length when they are executed or openned.
       Infected programs will increase by either 1,154 or 1,160 bytes,
       depending on which variant is present, with the virus being located at
       the end of the infected program.  The file length increase will not be
       able to be seen if the virus is memory resident.  The program's date
       and time in the disk directory will not be altered.

       Systems infected with a member of the Naughty Hacker family may
       find file allocation errors when they execute the DOS ChkDsk program.
       These errors occur when the virus is memory resident as the adjusted
       directory information will not match the file allocation table.
       Executing the ChkDsk program with a /F option may result in corrupted
       programs.

       Another symptom which may be noticed on infected systems is an annoying
       "buzz" being emitted from the system speaker after the virus has been
       resident for awhile.  When this occurs, scrolling of the display or
       pressing keys on the keyboard will also result in a clicking noise.
       These sound effects occur with some members of this family, but not the
       later variants.

       It is unknown what the Naughty Hacker Family does besides replicate.

       Members of the Naughty Hacker Family are:
       Naughty Hacker-A : With an effective length of 1,160 bytes, this variant
            does not produce the sound effects of Naughty Hacker-B.  The
            text string "Sofia, Feb '91 Naughty Hacker" can be found at the
            end of infected files.
       Naughty Hacker-B : With an effective length of 1,154 bytes, this variant
            produces the sound effects described above.  It contains the text
            strings "Sofia,Jan 1991" and "(c) Naughty Hacker."  It appears to
            be an earlier version of Naughty Hacker-A.
       Horse : Very similar to Naughty Hacker-B, Horse is a minor variation.
            Like Naughty Hacker-B, it is 1,154 bytes in length and produces the
            sound effects indicated above.  The text string in this variant
            is: "Sofia,1991 (c) Naughty Hacker."
       Horse 2 : Horse 2 is very similar to Naughty Hacker-A.  It is 1,160
            bytes in length, and produces no sound effects.  The text string
            in this variant is: "Sofia,Feb '91 Naughty Hacker."


 Virus Name:  New Jerusalem
 Aliases:
 V Status:    Rare
 Discovered:  October, 1989
 Symptoms:    TSR; .EXE, .COM, etc. (see below) growth; system slowdown;
              deleted files on Friday 13th
 Origin:      Holland
 Eff Length:  1,813 Bytes (.COM) & 1,808 Bytes (.EXE)
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V45+, F-Prot, Pro-Scan 1.4+
 Removal Instructions:  Saturday, CleanUp, F-Prot, Pro-Scan 1.4+
 General Comments:
       New Jerusalem is a variation of the original Jerusalem virus
       which has been modified to be undetectable by ViruScan versions
       prior to V45 as well as IBM's VIRSCAN product as of October 20,
       1989.  The virus was first detected when it was uploaded to
       several BBSs in Holland beginning on October 14, 1989.  It
       infects both .EXE and .COM files and activates on any Friday The
       13th, deleting infected programs when they are attempted to be
       run.

       This virus is memory resident, and as with other Jerusalem
       viruses, may infect overlay, .SYS, .BIN, and .PIF files.

       Also see: Jerusalem, Jerusalem B, Payday, Suriv 3.00


 Virus Name:  Nina
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM growth; decrease in total system and available free memory;
 Origin:      Bulgaria
 Eff Length:  256 Bytes
 Type Code:   PRhCK - Parasitic Resident .COM & Infector
 Detection Method:  ViruScan V74+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Nina Virus was received in December, 1990, and is from Bulgaria.
       This virus is a memory resident infector of .COM files, including
       COMMAND.COM.

       When the first program infected with the Nina Virus is executed, Nina
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  Total system memory and available free
       memory will decrease by 1,024 bytes as shown by the DOS ChkDsk command.
       Interrupt 21 will be hooked by the virus.

       After Nina is memory resident, it will infect .COM programs that are
       greater than 256 bytes in length as they are executed.  If COMMAND.COM
       is executed, it will become infected.  Infected .COM programs increase
       in length by 256 bytes, and will have the virus located at the beginning
       of the infected file.

       The Nina Virus is named Nina because the virus contains the text
       string "Nina" within the viral code.

       This virus does not do anything besides replicate.


 Virus Name:  Nomenklatura
 Aliases:     Nomenclature, 1024-B
 V Status:    Rare
 Discovered:  August, 1990
 Symptoms:    .EXE, .COM growth; decrease in available free memory;
              "sector not found" messages on diskettes;
 Origin:      Netherlands
 Eff Length:  1,024 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions:  Scan/D or Delete infected files
 General Comments:
       The Nomenklatura Virus was isolated in August, 1990 in the
       Netherlands.  This virus is a memory resident infector of .COM and
       .EXE files, including COMMAND.COM.  It is not related to the V1024
       virus, though it is the same length.

       The first time a program infected with the Nomenklatura Virus is
       executed on a system, the virus installs itself memory resident at
       the top of available system memory, but below the 640K DOS boundary.
       Available system memory will decrease by 1,024 bytes, and interrupt
       21 will be hooked by the virus.

       When the virus is memory resident, any .COM or .EXE program greater in
       length then approximately 1,023 bytes that is executed or openned
       for any reason will be infected by the Nomenklatura virus.  Infected
       files will have their file lengths increased by 1,024 bytes.  The
       virus does not hide the increase in file length when the disk directory
       is displayed.

       Attempts to execute uninfected programs from a write-protected diskette
       with the virus in memory will result in a "Sector not found error"
       message being displayed, and the program not being executed.

       The Nomenklatura Virus is destructive to the contents of diskettes
       exposed to infected systems.  File corruption will randomly occur,
       with the frequency increasing as the disk becomes more filled with data.
       The file errors may occur on data files as well program files.  This
       file corruption occurs due to the virus occassionally swapping a pair of
       words in the sector buffer.  It may also do this to critical system
       areas such as the FAT, boot sector, or directories since it may occur
       to any clusters on the disk.  If a file or critical system area was
       residing in a corrupted cluster, it will be corrupted.  As such, systems
       which has been exposed to the Nomenklatura Virus must be carefully
       checked as the integrity of non-infected programs and any datafiles
       should be considered suspect.

       The virus has been named Nomenklatura as this text string appears in
       all programs infected with this virus.


 Virus Name:  Number One
 Aliases:     Number 1
 V Status:    Extinct
 Discovered:  1987 (see below)
 Symptoms:    .COM files fail to function; <Smile> displayed
 Origin:      West Germany
 Eff Length:  12,032 Bytes
 Type Code:   ONC - Overwriting Non-Resident .COM Infector
 Detection Method:
 Removal Instructions:  Scan/D or Delete infected files
 General Comments:
       The Number One Virus was submitted for inclusion in this listing in
       September, 1990.  This virus, however, is not a new virus but is an
       extinct rather "old" virus.  The Number One Virus was written in
       October, 1987, by M. Vallen using Turbo Pascal 3.01A.  It is
       documented, complete with source, in a book by Ralf Burger.  This
       virus is an non-resident overwriting virus which infects .COM files.

       When a program infected with the Number One Virus is executed, the virus
       will infect the first uninfected .COM file it finds in the current
       directory.  If the .COM file was originally less than 12,032 bytes in
       length, it will now have a 12,032 bytes.  Infected files will also have
       their date/timestamps in the directory changed to reflect the time of
       infection.  After Number One has finished infecting a .COM file, it will
       display the message:

               "This File Has Been Infected by Number One!
                XXXXXXXX.COMinfected."

       The XXXXXXXX is the name of the .COM file that has just been infected
       by the virus.  When there are no more .COM files for Number One to
       infect in the current directory, it will display the following
       message:

                "This File Has Been Infected by Number One!
                 <Smile>"

       Number One will not infect any files which have the Read Only Attribute
       set.

       Since Number One is an overwriting virus, it is not possible to
       remove the virus from infected files and repair the damage.  Infected
       files should be erased and replaced with clean copies.


 Virus Name:  Ohio
 Aliases:
 V Status:    Common
 Discovered:  June, 1988
 Symptoms:    BSC, Resident TOM
 Origin:      Indonesia
 Eff Length:  N/A
 Type Code:   RtF - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+
 Removal Instructions:  MDisk, F-Prot, VirexPC, Pro-Scan 1.4+,
              or DOS SYS Command
 General Comments:
       The Ohio virus is a memory resident boot sector infector, only
       infecting 360K floppy disks.  The Ohio virus is similar in
       many respects to the Den Zuk virus, and is believed to possibly
       be the earlier version of Den Zuk.  A diskette infected with
       Ohio will be immune to infection by the Pakistani Brain virus.

       The following text strings appear in the Ohio virus:

                "V  I  R  U  S
                      b y
                  The Hackers
                  Y C 1 E R P
                 D E N Z U K 0
                 Bandung 40254
                   Indonesia

           (C) 1988, The Hackers Team...."

       Also see: Den Zuk


 Virus Name:  Ontario
 Aliases:
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    .COM & .EXE growth; decrease in system and free memory;
              hard disk errors in the case of extreme infections
 Origin:      Ontario, Canada
 Eff Length:  512 Bytes
 Type Code:   PRtAK - Parasitic Encrypted Resident .COM & .EXE Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+, NAV
 Removal Instructions:  SCAN /D, or Delete infected files
 General Comments:
       The Ontario Virus was isolated by Mike Shields in Ontario, Canada
       in July, 1990.  The Ontario virus is a memory resident infector of
       .COM, .EXE, and overlay files.  It will infect COMMAND.COM.

       The first time a program infected with the Ontario Virus is executed,
       it will install itself memory resident above the top of system memory
       but below the 640K DOS boundary.  Total system memory and free memory
       will be decreased by 2,048 bytes.  At this time, the virus will
       infect COMMAND.COM on the C: drive, increasing its length by 512 bytes.

       Each time an uninfected program is executed on the system with the
       virus memory resident, the program will become infected with the viral
       code located at the end of the file.  For .COM files, they will
       increase by 512 bytes in all cases.  For .EXE and overlay files, the
       file length increase will be 512 - 1023 bytes.  The difference in
       length for .EXE and overlay files is because the virus will fill out
       the unused space at the end of the last sector of the uninfected file
       with random data (usually a portion of the directory) and then append
       itself to the end of the file at the next sector.  Systems using
       a sector size of more than 512 bytes may notice larger file increases
       for infected files.  Infected files will always have a file length
       that is a multiple of the sector size on the disk.

       In the case of extreme infections of the Ontario Virus, hard disk
       errors may be noticed.

       Ontario uses a complex encryption routine, and a simple identification
       string will not identify this virus.


 Virus Name:  Oropax
 Aliases:     Music Virus, Musician
 V Status:    Rare
 Discovered:  December, 1989
 Symptoms:    .COM growth, tunes
 Origin:
 Eff Length:  2,756 - 2,806 bytes, but usually 2,773 bytes
 Type Code:   PRC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V53+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  SCAN /D, F-Prot, VirexPC, Pro-Scan 1.4+, VirHunt 2.0+
              or delete infected files
 General Comments:
       The Oropax virus has had several reports, but wasn't first isolated
       until December 1989.  It infects .COM files, increasing their length
       by between 2,756 bytes and 2,806 bytes.  Infected files will always
       have a length divisible by 51.  The virus may become active (on a
       random basis) five minutes after infection of a file, playing three
       different tunes with a seven minute interval in between.

       One variant recently reported in Europe plays six different
       tunes at seven minute intervals.


 Virus Name:  Paris
 Aliases:
 V Status:    Rare
 Discovery:   August, 1990
 Symptoms:    .COM & .EXE file growth; slow program loads upon execution;
              Diskette corruption after diskette boot
 Origin:      Paris, France
 Eff Length:  4,909 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method: ViruScan V66+, Pro-Scan 2.01+, NAV
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Paris Virus was isolated in Paris, France, in early August, 1990.
       This virus is a generic infector of .COM, .EXE and overlay files,
       and will infect COMMAND.COM.  It is not memory resident.

       When a program infected with the Paris Virus is executed, the virus
       will infect all .COM, .EXE and overlay files on the current drive
       and directory, with the exception of very small .COM files.  It will
       also check to see if COMMAND.COM on the C: drive is uninfected, if it
       has not previously been infected it will become infected.  Infected
       files will increase in length by between 4,909 - 4, 25 bytes, with the
       virus located at the end of the infected file.

       The Paris Virus can be destructive in some instances, resulting in
       diskettes becoming corrupted if the system is booted from a diskette
       with a Paris infected COMMAND.COM program.


 Virus Name:  Parity
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth; long .COM program loads;
              possibly intermittent parity errors
 Origin:      Bulgaria
 Eff Length:  441 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM  Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Parity Virus was received in December, 1990, and originated in
       Bulgaria.  This virus is a non-memory resident infector of .COM files,
       and will infect COMMAND.COM.

       When a program infected with the Parity Virus is executed, the virus
       will infect all .COM files in the current directory.  If COMMAND.COM
       is in the current directory, it will become infected.

       Infected .COM programs will increase in length by 441 bytes, the virus
       being located at the end of the infected program.  The program's date
       and time in the disk directory will not be altered by the virus.

       The major symptom of a Parity Virus infection is that it will take
       significantly longer to load and execute infected .COM files.  The
       increase in time is due to the virus searching the current drive for
       .COM files to infect.

       This virus may also display a message "PARITY CHECK 2" at times, and
       halt the system.


 Virus Name:  Payday
 Aliases:
 V Status:    Rare
 Discovered:  November, 1989
 Symptoms:    TSR, .EXE & .COM growth, system slowdown, deleted files
              on Friday EXCEPT 13th, "Black WIndow"
 Origin:      Netherlands
 Eff Length:  1,808 Bytes (.EXE) & 1,813 Bytes (.COM)
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V51+, F-Prot, Pro-Scan 1.4+, AVTK 3.5+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions:  UnVirus, Saturday, CleanUp, F-Prot, Pro-Scan 1.4+,
              NAV
 General Comments:
       The Payday virus was isolated by Jan Terpstra of the Netherlands
       in November, 1989.  It is a variant of the Jerusalem B virus,
       the major difference being that the activation criteria to
       delete files has been changed from every Friday The 13th to
       any Friday but Friday The 13ths.

       Also see: Jerusalem, Jerusalem B, New Jerusalem, Suriv 3.00


 Virus Name:  Pentagon
 Aliases:
 V Status:    Extinct
 Discovered:  January, 1988
 Symptoms:    TSR, BSC 360k floppies, file (see text)
 Origin:      USA
 Eff Length:  N/A
 Type Code:   RF - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, VirexPC
 Removal Instructions: MDisk, CleanUp, or DOS SYS Command
 General Comments:
       The Pentagon virus consists of a normal MS-DOS 3.20 boot
       sector where the name 'IBM' has been replaced by 'HAL', along
       with two files.  The first file has a name of the hex
       character 0F9H, and contains the portion of the virus code
       which would not fit into the boot sector, as well as the
       original boot sector of the infected disk.  The second file
       is named PENTAGON.TXT and does not appear to be used or contain
       any data.  The 0F9H file is accessed by its absolute storage
       address.  Portions of this virus are encrypted.

       The Pentagon virus only infects 360K floppies, and will look
       for and remove the Brain virus from any disk that it infects.
       It is memory resident, occupying 5K of RAM, and can survive
       a warm reboot or CTL-ALT-DEL.


 Virus Name:  Perfume
 Aliases:     765, 4711
 V Status:    Endangered
 Discovered:  December, 1989
 Symptoms:    .COM growth, messages
 Origin:      Germany
 Eff Length:  765 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method: ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, F-Prot, Pro-Scan 1.4+, VirHunt 2.0+, NAV,
              or delete infected files
 General Comments:
       The Perfume virus is of German origin, and has also been
       isolated in Poland in December, 1989.  This virus infects
       .COM files, and will look for COMMAND.COM and infect it if
       it isn't already infected.  Infected files always grow in
       length by 765 bytes.

       The virus will sometimes ask the system user a question,
       and then not run the infected program unless the system
       user responds by typing 4711, the name of a German perfume.

       In the most common variant of this virus, however, the
       questions have been overwritten with miscellaneous
       characters.

       Also see: Sorry


 Virus Name:  Phantom
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; Message; Shift of System Display;
              Decrease in total system and available memory
 Origin:      Hungary
 Eff Length:  2,274 Bytes
 Type Code:   PRhC - Parasitic Resident .COM Infector
 Detection Method: ViruScan V75+
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The Phantom Virus was isolated in Hungary in January, 1991, by Dr.
       Szegedi Imre.  This virus is a memory resident infector of .COM files,
       but not COMMAND.COM.

       The first time a program infected with the Phantom Virus is executed,
       the Phantom Virus will install itself memory resident at the top of
       system memory but below the 640K DOS boundary.  Infected systems will
       have interrupts 20 and 21 hooked by the virus, and the DOS ChkDsk
       program will report total system and available memory as 2,704 bytes
       less than expected.

       After becoming memory resident, the Phantom Virus will infect .COM
       programs as they are executed or openned if the original file length
       is greater than 2K.  Infected programs will increase in size by 2,274
       bytes with the virus being located at the end of infected programs.

       Systems infected with the Phantom Virus will experience the following
       message being displayed intermittently when programs are executed:

               "HI ROOKIE!
                I`m a THESEASE! I live in YOUR computer - sorry...
                Thanks to Brains in the Computer Siences!"

       This message, as with the following text strings which also occur in
       the virus's code, cannot be seen in infected programs as they are
       encrypted.  The other text strings which are encrypted in the viral
       code are:

               "The PHANTOM Was HERE - SORRY"
               "(c) PHANTOM  -  This virus was designed in the HUNGARIAN
                VIRUS DEVELOPING LABORATORY. (H.V.D.L.) v1.0"

       Another symptom of the Phantom Virus is that it will occasionally
       alter the system display so that what should start on the left side of
       the screen starts in the middle (it is shifted 50% with wrap around on
       the same line).


 Virus Name:  Phoenix
 Aliases:     P1
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    .COM growth, system reboots, CHKDSK program failure,
              COMMAND.COM header change
 Origin:      Bulgaria
 Eff Length:  1,704 Bytes
 Type Code:   PRhCK - Parasitic Resident .COM Infector
 Detection Method: ViruScan V66+, Pro-Scan 2.01+, NAV
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The Phoenix virus is of Bulgarian origin, and was submitted to
       the author of this document in July, 1990 by Vesselin Bontchev.
       This virus is one of a family of three (3) viruses which may be
       referred to as the P1 or Phoenix Family.  Each of these viruses is
       being documented separately due to their varying characteristics.
       The Phoenix virus is a memory resident, generic infector of .COM
       files, and will infect COMMAND.COM.

       The first time a program infected with the Phoenix virus is executed,
       the virus will install itself memory resident in free high memory,
       reserving 8,192 bytes.  Interrupt 2A will be hooked by the virus.
       System total memory and free memory will decrease by 8,192 bytes.
       If the program was executed from a floppy drive, and COMMAND.COM was
       not present on the diskette, the virus will request that a diskette
       with \COMMAND.COM present be inserted in the drive.  Phoenix will
       immediately infect COMMAND.COM by overwriting part of the binary zero
       portion of the program, and changing the program's header information.
       COMMAND.COM will not change in file length.  The virus will then
       similarly infect COMMAND.COM residing in the C: drive root directory.

       After becoming memory resident, the virus will attempt to infect any
       .COM file executed.  Most of its attempts, however, will not result in
       a file being infected.  Phoenix is a fairly poor replicator.  If the
       virus is successful in infecting the file, it will append its viral
       code to the end of the file, increasing the file's length by 1,704
       bytes.

       Phoenix is not able to recognize when it has previously infected a file,
       so it may reinfect .COM files several times.  Each infection will
       result in another 1,704 bytes of viral code being appended to the
       file.

       Systems infected with the Phoenix virus will experience problems with
       executing CHKDSK.COM.  Attempts to execute this program with Phoenix
       memory resident will result in a warm reboot of the system occurring,
       however the memory resident version of Phoenix will not survive the
       reboot.  If an autoexec.bat file is not present on the drive being
       booted from, the system will prompt for the user to enter Date and
       Time.

       The Phoenix Virus employs a complex encryption mechanism, and virus
       scanners which are only able to look for simple hex strings will not
       be able to detect it.  There is no simple hex string in this virus
       that is common to all infected samples.

       This virus is not related to the Cascade (1701/1704) Virus.

       Also see: Evil, PhoenixD


 Virus Name:  PhoenixD
 Aliases:     P1
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    .COM growth, system reboots, CHKDSK program failure,
              COMMAND.COM header change
 Origin:      Bulgaria
 Eff Length:  1,704 Bytes
 Type Code:   PRhCK - Parasitic Resident .COM Infector
 Detection Method: ViruScan V66+, Pro-Scan 2.01+, NAV
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The PhoenixD virus is of Bulgarian origin, and was submitted to
       the author of this document in July, 1990 by Vesselin Bontchev.
       This virus is one of a family of three (3) viruses which may be
       referred to as the P1 or Phoenix Family.  Each of these viruses is
       being documented separately due to their varying characteristics.
       The PhoenixD virus is a memory resident, generic infector of .COM
       files, and will infect COMMAND.COM.

       The PhoenixD Virus is a "bug fixed" version of the Phoenix virus.

       The first time a program infected with the PhoenixD virus is executed,
       the virus will install itself memory resident in free high memory,
       reserving 8,192 bytes.  Interrupt 2A will be hooked by the virus.
       System total memory and free memory will decrease by 8,192 bytes.
       PhoenixD will then check to see if the current drive's root directory
       contains a copy of COMMAND.COM.  If a copy of COMMAND.COM is found,
       it will be infected by PhoenixD by overwriting part of the binary zero
       portion of the program, and changing the program's header information.
       COMMAND.COM will not change in file length.  The virus will then
       similarly infect COMMAND.COM residing in the C: drive root directory.

       After becoming memory resident, the virus will attempt to infect any
       .COM file executed.  PhoenixD is a much better replicator than the
       original Phoenix Virus, and is usually able to infect files.  Infected
       files will increase in length by 1,704 bytes.

       PhoenixD is not able to recognize when it has previously infected a
       file, so it may reinfect .COM files several times.  Each infection will
       result in another 1,704 bytes of viral code being appended to the
       file.

       A characteristic present in the PhoenixD Virus which is not found in
       the original Phoenix Virus is that in addition to it infecting .COM
       files as they are executed, .COM files will be infected when they
       are opened for any reason.  The simple act of copying a .COM file
       with PhoenixD present in memory will result in both the source and
       target files being infected.

       Systems infected with the PhoenixD virus will experience problems with
       executing CHKDSK.COM.  Attempts to execute this program with Phoenix
       memory resident will result in a warm reboot of the system occurring.
       If an autoexec.bat file is not present on the drive being booted from,
       the system will prompt for the user to enter Date and Time.

       The PhoenixD Virus employs a complex encryption mechanism, and virus
       scanners which are only able to look for simple hex strings will not
       be able to detect it.  There is no simple hex string in this virus
       that is common to all infected samples.

       This virus is not related to the Cascade (1701/1704) virus.

       Also see: Evil, Phoenix


 Virus Name:  Ping Pong
 Aliases:     Bouncing Ball, Bouncing Dot, Italian, Vera Cruz
 V Status:    Extinct
 Discovered:  March, 1988
 Symptoms:    Graphic display (see text), TSR, BSC
 Origin:
 Eff Length:  N/A
 Type Code:   RsF - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, VirexPC, Pro-Scan,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  MDisk, CleanUp, F-Prot, Pro-Scan 1.4+, VirexPC, NAV,
              or DOS SYS command
 General Comments:
       The Ping Pong virus is a boot sector virus which was first
       reported in March 1988.  The original Ping Pong virus only
       infects Floppy Disks.

       When the virus activates, which is on a random basis, a
       bouncing ball or dot appears on the screen.  This display
       can only be stopped thru a system reboot.  No other damage
       is apparently done.

       The Ping Pong Virus is extinct, though the hard disk variant,
       Ping Pong-B listed below, is one of the most common MS-DOS
       viruses.


 Virus Name:  Ping Pong-B
 Aliases:     Bouncing Ball Boot, Italian-A
 V Status:    Common
 Discovered:  May, 1988
 Symptoms:    Graphic display (see text), TSR, BSC
 Origin:
 Eff Length:  N/A
 Type Code:   BRs - Resident Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: CleanUp, MDisk, Pro-Scan 1.4+, F-Prot, VirexPC, NAV,
              or DOS SYS Command
 General Comments:
       The Ping Pong-B virus is a variant of the Ping Pong virus.  The
       major difference is that Ping Pong-B can infect hard disks as
       well as floppies.

       Known variants of Ping Pong-B include:
       Ping Pong-C : Similar to Ping Pong-B, though this variant does
            not have the bouncing ball screen effect.
            Origin: Argentina, June 1990.


 Virus Name:  Plastique
 Aliases:     Plastic Bomb, Plastique 3012, Plastique 1
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    TSR; .COM & .EXE growth; possible system slowdown or bomb
              noises after September 20
 Origin:      Taiwan
 Eff Length:  3,012 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Clean-Up V72+, Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The Plastique, or Plastic Bomb, Virus was submitted in July 1990, it
       comes to us from Taiwan.  Plastique is a memory resident generic
       infector of .COM and .EXE files, though it does not infect
       COMMAND.COM.  Unlike the Plastique-B Virus listed below, this virus
       does not infect floppy disk boot sectors.

       The first time a program infected with Plastique is executed, the
       virus will install itself memory resident as a TSR in low system
       memory.  The TSR is 3,264 bytes in length, and hooks interrupt 21.

       After the virus is memory resident, it will attempt to infect any
       .COM or .EXE file which is executed.  This virus is rather "buggy",
       and it is not always successful in infecting files when they are
       executed.  When it is successful infecting the file, the file's
       length will increase.  For infected .COM files, the length will
       increase by 3,012 bytes.  For infected .EXE files, their length
       will increase between 3,012 and 3,020 bytes.

       Plastique will also attempt to infect files when they are opened for
       any reason, though again, it is not always successful.

       After September 20th of any year, the Plastique Virus activates.  At
       that time, it will do either of two things.  It will either
       progressively slowdown the system, or it will intermittently emit
       "bomb" noises from the system speaker.

       Known variant(s) of Plastique are:
       HM2            : The earliest known version of this virus, it does
                        not replicate.  Executing an infected file results
                        in the system hanging requiring a reboot.
                        Origin: Taiwan, May 1990.
       Plastique 4.51 : A variant of the Plastique virus described above,
                        the only real difference is that the encryption
                        of the virus is slightly different.  Otherwise it
                        behaves exactly the same as Plastique.
                        Origin: Taiwan, July 1990.
       Plastique COBOL: A variant of the Plastique virus described above, this
                        version is 3,004 bytes in length, and its memory
                        resident TSR is 3,248 bytes in length.  The only text
                        character string which can be found in this variant is
                        "COBOL".  This string does not occur in other variants
                        of the Plastique Virus, or related viruses.  Infected
                        .COM programs will increase in size by 3,004 bytes,
                        .EXE files by 3,004 to 3,019 bytes.  COMMAND.COM will
                        not become infected.  Activation of the virus has also
                        been altered.  Between January 1 and September 21, the
                        virus will progressively slowdown the system.  After 20
                        minutes, the system will execute at approximately 50%
                        of its original speed.  After 30 minutes, the virus
                        may lockout the system keyboard, as well as corrupt
                        the system's CMOS configuration.  Between September 22
                        and December 31, the virus does not activate, and no
                        system slowdown or CMOS corruption will occur.

       Also see: Invader, Plastique-B


 Virus Name:  Plastique-B
 Aliases:     Plastic Bomb, Plastique 5.21, Plastique 2
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    TSR, .COM & .EXE file growth; BSC;
 Origin:      Taiwan
 Eff Length:  4,096 Bytes
 Type Code:   PRsAB - Parasitic Resident .COM & .EXE, & Boot Sector Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Clean-Up V72+, Pro-Scan 2.01+, or Delete Infected Files
 General Comments:
       The Plastique-B, or Plastique 5.21, virus is a later version of
       the Plastique virus.  Like Plastique, it is a memory resident
       generic infector of .COM and .EXE files.  This version will also
       infect diskette boot sectors.  It does not infect COMMAND.COM.

       If the system date is before September 20th, the first time a program
       infected with Plastique-B is executed, the virus will install itself
       memory resident as a TSR in low system memory.  The TSR is 5,120 bytes
       in length.  Interrupts 08, 09, 13, 21, and ED are hooked by the virus.

       If the system date is after September 20th, the virus will install
       itself memory resident in high system memory but below the 640K DOS
       boundary.  The same interrupts will be hooked by the virus.

       After the virus is memory resident, it will attempt to infect any
       .COM or .EXE file which is executed or opened for any reason.  It
       has had many of the "bugs" fixed that were in Plastique, and is
       usually successful in infecting files.  Infected .COM and .EXE files
       will increase in length by 4,096 bytes.

       Plastique-B will also infect the boot sector of any diskettes accessed
       on an infected system.

       After September 20th, 1990, the Plastique-B virus activates. It
       will either progressively slowdown the system or cause "bomb" noises
       to be emitted periodically from the system speaker.  It may also
       overwrite the contents of all drives after this date, depending on if
       a predetermined limit in the virus has been reached.

       Also see: Plastique, Invader


 Virus Name:  Polimer
 Aliases:     Polimer Tapeworm
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    .COM growth; Message
 Origin:      Hungary
 Eff Length:  512 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Polimer Virus was discovered in Hungary in November, 1990.  This
       virus is a non-resident infector of .COM files, including COMMAND.COM.

       When a program infected with the Polimer Virus is executed, the
       following message will be displayed:

               "A le' jobb kazetta a POLIMER kazetta !   Vegye ezt !"

       This message can be found near the beginning of all infected files.

       After the message is displayed, the virus will attempt to infect one
       .COM file on the current drive and directory, and one .COM file on the
       C: drive's current directory.  This virus will only infect .COM files
       which are between 512 and 64,758 bytes in length.  If the .COM file it
       attempts to infect has the Read-Only attribute, it will not be infected,
       and the message $ERROR will be displayed.

       Although this virus is actually 456 bytes in length, infected .COM files
       will increase in size by 512 bytes with the virus's code being located
       at the beginning of the file.

       This virus does not appear to do anything besides replicating.


 Virus Name:  Polish 217
 Aliases:     217, Polish Stupid
 V Status:    Rare
 Discovered:  October, 1990
 Symptoms:    .COM growth; system reboot
 Origin:      Koszalin, Poland
 Eff Length:  217 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V71+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Polish 217, or Polish Stupid, Virus was discovered in Koszalin,
       Poland, in October, 1990.  This virus is a non-resident infector of
       .COM files, including COMMAND.COM.

       When a program infected with the Polish Stupid Virus is executed, the
       virus will infect the first uninfected .COM file found in the current
       directory.  Infected .COM files will increase in length by 217 bytes
       with the virus's code being located at the end of the file.  Infected
       files will also end with the hex string 5757h.  The file's date and
       time in the disk directory is not altered.

       A side note on this virus: when the copy of COMMAND.COM pointed to by
       the COMSPEC environmental variable is infected by the virus, the system
       will experience a warm reboot.

       This virus does nothing besides replicating in its current version.

       Known variant(s) of Polish 217 are:
       Polish 217 B : The Polish 217 B variant's major difference is that
               when COMMAND.COM is infected, a warm reboot does not occur.
               Execution of COMMAND.COM will result in the error message:
               "Specified COMMAND search directory bad".  Execution of
               infected programs may also result in the following message
               being displayed and the program terminated:
                   "????????COM
                    Path not found."
               Programs which can detect Polish 217 may not be able to detect
               Polish 217 B as it has been altered.  Scan V72 and below will
               not detect it.


 Virus Name:  Polish 529
 Aliases:     529
 V Status:    Rare
 Discovered:  September, 1990
 Symptoms:    .COM growth; TSR
 Origin:      Poland
 Eff Length:  529 Bytes
 Type Code:   PRsCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V71+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Polish 529 Virus was isolated in September, 1990 in Poland.  This
       virus is a memory resident infector of .COM files.  It will infect
       COMMAND.COM if it is executed with the virus in memory.

       The first time a program infected with the Polish 529 Virus is executed,
       the virus will install itself memory resident as a low system memory
       TSR of 1,664 bytes.  Interrupt 21 will be hooked by the virus.

       Once the virus is memory resident, any .COM file over approximately
       1600 bytes in length will be infected by the virus.  Infected .COM
       files will show a file length increase of 529 bytes and have the
       virus's code located at the beginning of the file.

       This virus does not appear to do anything but replicate.


 Virus Name:  Polish 583
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth
 Origin:      Poland
 Eff Length:  583 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Polish 583 Virus originated in Poland and was submitted in
       December, 1990.  This virus is a non-resident, direct action infector
       of .COM files, including COMMAND.COM.

       When a program infected with Polish 583 is executed, the virus will
       infect one other .COM file on the current drive and directory.  The
       newly infected program will increase in length by 583 bytes with the
       virus's code being located at the end of the infected program.  The
       program's date and time in the disk directory is not altered.

       This virus does not do anything besides replicate.



 Virus Name:  Print Screen
 Aliases:     EB 21, 8290, PRTSC Virus
 V Status:    Rare
 Discovered:  November, 1989
 Symptoms:    BSC, hard disk access slowdown
 Origin:      Bombay, India
 Eff Length:  N/A
 Type Code:   BR - Resident Boot Sector Infector
 Detection Method:  ViruScan V64+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: CleanUp V77+, M-Disk, Pro-Scan 1.4+, NAV, or
              DOS SYS Command
 General Comments:
       The Print Screen Virus was isolated in Bombay, India in November, 1989
       by Neville Bulsara.  It is the first virus to have originated in
       India.  There are two versions of Print Screen, the later version
       having had some bugs fixed.

       When a system is booted from a Print Screen infected diskette or
       hard drive, the virus will install itself memory resident in the
       top of memory.  The virus then adjusts the amount of memory DOS
       thinks is installed.  Infected systems will show that total system
       memory is 2K less than is installed.  On floppy disks, the original
       boot sector of the diskette will be copied to sector 11.

       After becoming memory resident, the virus will infect any hard
       disk or floppy diskette which is accessed by the system.

       Infected system users will notice that hard disk accesses done for
       any reason will be much slower than expected.  In some cases,
       listing the root directory will show apparently garbage entries in
       it.  These entries are actually part of the virus's code.

       The first version of the Print Screen virus is buggy, and as such
       it doesn't actually accomplish anything having to do with printing
       screens.

       This virus appears to have been based on the Ping Pong Virus, and
       some anti-viral programs will identify it as such.

       Known variant(s) of Print Screen are:
       Print Screen-2: Print Screen-2 is the later, bug fixed version of
            the Print Screen Virus.  This version will attempt to perform
            a screen print or dump to the system's printer after every
            255 disk I/Os have occurred.


 Virus Name:  Proud
 Aliases:     V1302, P1 Related
 V Status:    Rare
 Discovery:   August, 1990
 Symptoms:    .COM growth; decrease in total system and available memory;
              FAT entry corruption
 Origin:      Bulgaria
 Eff Length:  1,302 Bytes
 Type Code:   PRtCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V71+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Proud, or V1302, Virus was isolated in August of 1990 in Bulgaria
       by Vesselin Bontchev.  Proud is a memory resident infector of .COM
       files, including COMMAND.COM.

       The first time a program infected with Proud is executed, the virus
       checks to determine if interrupt 13 is in use by another program, and
       if it is, the virus will hang the system.  If interrupt 13 is not in
       use by another program, Proud will install itself memory resident at
       the top of system memory, but below the 640K DOS boundary.  Total
       system memory and free available memory will decrease by 8,192 bytes.
       Interrupt 2A will be replaced by the virus.

       Once the virus is memory resident, it will infect .COM files within
       certain candidate length ranges whend they are openned for any reason.
       The candidate file length ranges are:

                2,048 - 14,335 bytes
               16,384 - 30,719 bytes
               32,768 - 47,103 bytes
               49,152 - 63,487 bytes

       Proud is an encrypted virus, and is unusual in that it "splits"
       the .COM file being infected into two parts, placing the viral code
       between the two sections.  Proud also is unable to distinguish when
       a file has been previously infected, so .COM files can become infected
       multiple times.  Each infection, with the exception of COMMAND.COM,
       will add 1,302 bytes to the file length.  Infected COMMAND.COM files
       generally don't increase in length on the first infection as the virus
       will overwrite part of the 00h area of COMMAND.COM with the viral code.

       Proud can be a damaging virus, with a probability of 1 out of 256, it
       may swap entries in the file allocation table.


 Virus Name:  RaubKopie
 Aliases:
 V Status:    Rare
 Discovery:   March, 1991
 Symptoms:    .COM & .EXE growth; Messages
 Origin:      Germany
 Eff Length:  2,219 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method: ViruScan V76+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The RaubKopie Virus was submitted in March, 1991 by Jan Terpstra of
       the Netherlands.  It is originally from Germany.  Raubkopie is a
       non-resident direct action infector of .COM and .EXE files.  It will
       infect COMMAND.COM.

       When a program infected with RaubKopie is executed, the virus will
       infect up to five .COM programs in the currect directory.  If less than
       five uninfected .COM programs existed in the current directory, it will
       then infect .EXE files until the total number of programs it has
       infected on this execution totals five.

       .COM programs infected with Raubkopie will increase in size by 2,219
       bytes with the virus being located at the beginning of the infected
       file.  The program's date and time in the disk directory will not be
       altered.

       .EXE programs infected with Raubkopie will increase in size by 2,475
       to 2,491 bytes with the virus being located at the end of the file.
       The larger file size increase with .EXE files is due to a different
       mechanism being used to infect the programs.  With .EXE files, the
       virus will first add up to 16 bytes to the candidate .EXE file so that
       the program's length is now divisible by 16.  After adding the
       additional bytes, it then adds 256 bytes of hex 00's and appends the
       Raubkopie code to the end of the program.  The program's date and
       time in the disk directory will not be altered.

       The RaubKopie Virus will occassionally display messages and require
       a response when an infected program is invoked.  The messages displayed
       cannot be seen within infected programs, they are encrypted.  The
       first message displayed when the messages occur is:

               "           A C H T U N G
                    ---------------------------

                Die Benutzung einer RAUBKOPIE ist strafbar!
                Nur wer Original-Disketten, Handbucher,
                oder PD-Lizenzen besitzt, darf Kopien verwenden.

                Programmierung is muhevolle Detailarbeit:
                Wer Raubkopien verwendet, betrugt
                Programmierer un den Lohn ihrer Arbeit.

                    ---------------------------           "

       A pause will then occur, and the following question will be displayed:

               "Bist Du sauber ? (J/N) "

       Entering "J" for yes will result in the following message being
       displayed and the program which the user was attempting to execute
       will proceed to execute:

               "Ich will glauben, was Du sagst ..... "

        Entering "N" for no will result in the following messages, the second
        of which is garbled, and the program the user was attempting to execute
        will be terminated:

               "CPU-ID wird gespeichert...

                **** LO<garbled>            "

        The last garbled message in original samples of this virus is:

               "**** Losche dieses Programm ****".

        There is also code within the RaubKopie virus to format the boot
        sector of the system hard disk if the system date is greater than the
        12th of the month, or the hour is above 17:00 (5:00 PM).  This code,
        however, does not function properly due to a bug within the RaubKopie
        Virus.

        Besides the messages and file growth, infected systems may have some
        of the directories containing RaubKopie infected programs sorted so
        that .COM files appear at the beginning of the directory listing.


 Virus Name:  Red Diavolyata
 Aliases:     USSR 830
 V Status:    Rare
 Discovery:   December, 1990
 Symptoms:    .COM growth; decrease in system and available memory;
              file date/time changes
 Origin:      USSR
 Eff Length:  830 Bytes
 Type Code:   PRhCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Red Diavolyata Virus is an 830 byte memory resident infector of
       .COM files, including COMMAND.COM.  It was submitted in December, 1990,
       and originated in the USSR.

       The first time a program infected with Red Diavolyata is executed, the
       virus will install itself memory resident at the top of system memory
       but below the 640K DOS boundary.  The interrupt 12 return is not moved.
       The DOS ChkDsk command will indicate that total system memory and
       available free memory have decreased by 960 bytes.  Interrupt 21 will
       be hooked by the virus.

       Once Red Diavolyata is memory resident, any .COM program executed will
       become infected by the virus.  If COMMAND.COM is executed, it will be
       infected.

       Infected .COM programs will have their file length increased by 830
       bytes, and their date and time in the disk directory will have been
       altered to the system date and time when infection occurred.  The virus
       will be located at the end of the infected program.

       The following text strings can be found at the end of infected
       programs:

               "Eddie die somewhere in time"
               "This programm was written in the city of Prostokwashino"
               "(C) 1990 RED DIAVOLYATA"
               "Hello! MLTI!"

       Additionally, the text string "MLTI!COMMAND" can be found within
       infected files.

       It is unknown if Red Diavolyata does anything besides replicate.


 Virus Name:  RPVS
 Aliases:     453
 V Status:    Endangered
 Discovery:   August, 1990
 Symptoms:    .COM growth
 Origin:      West Germany
 Eff Length:  453 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method: Pro-Scan 2.01+, ViruScan V76+, IBM Scan 2.00+
 Removal Instructions: Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The RPVS, or 453, Virus was discovered in West Germany in early
       August, 1990.  This virus is a non-resident infector of .COM files.
       The RPVS is named for an unusual string that appears in a file
       dump of the virus - "TUQ.RPVS" - this in not really a text string,
       but a series of PUSH instructions.

       The RPVS Virus is rather unsophisticated virus.  Whenever a .COM
       program infected with the RPVS or 453 virus is executed, the virus
       will look for an uninfected .COM file in the current directory.  The
       virus determines if the .COM file has been previously infected by
       checking to see if the last two bytes of the file are 9090h.  If the
       last two bytes are not 9090h, the file will be infected, appending
       453 bytes of viral code to the end of the file.  One .COM file is
       infected each time an infected program is executed.  COMMAND.COM
       will not normally be infected.

       This virus does not contain any logic to activate and cause damage
       in its current state.  It does contain many NOP instructions and odd
       jumps which leave plenty of space for later additions.

       Known variant(s) of RPVS are:
       RPVS-B : The RPVS virus after additional bytes have been added to the
                end of an infected program.  When this occurs, the virus
                will act differently.  It will not be able to determine that
                it has already infected a .COM file, so it will reinfect
                the first .COM file it finds in the current directory over
                and over again.


 Virus Name:  Saddam
 Aliases:     Sadam
 V Status:    Rare
 Discovery:   January, 1991
 Symptoms:    .COM growth; Message; Disk boot failures; I/O error message;
              "Insufficient memory" message when attempting to run .BAT files;
              Dir command errors; System hangs
 Origin:      France    (reported September, 1990)
 Isolated:    Israel
 Eff Length:  919 Bytes
 Type Code:   PRsCK - Resident Parasitic .COM Infector
 Detection Method:  ViruScan V74+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Saddam Virus was first reported in France in September, 1990.  In
       January, 1991, the first sample of this virus was actually received, its
       isolation point was Israel.  Saddam is a memory resident infector of
       .COM files, including COMMAND.COM.  It is based on the Do-Nothing virus.

       The first time a program infected with the Saddam Virus is executed,
       the virus will install itself memory resident in low system memory,
       though not as a TSR.  Interrupts 21 and 22 will be hooked by the virus.
       COMMAND.COM will be infected at this time if it has not previously
       been infected.

       Once Saddam is memory resident, it will infect .COM programs as they
       are executed or openned.  Infected .COM files will have a file length
       increase of 919 bytes, the virus will be located at the end of
       infected programs.  Programs infected with this virus will not have
       their file date and time altered upon infection.

       There are several symptoms which may be experienced on systems infected
       with the Saddam Virus.  The most obvious symptom is that the following
       message will occasionally be displayed:

               "HEY SADAM
                LEAVE QUEIT BEFORE I COME"

       This message cannot be seen in infected files, it is encrypted.

       Other symptoms are that attempts to execute .BAT files will result in
       an insufficient memory message.  Attempts to boot from a disk with a
       Saddam infected COMMAND.COM will fail, the system will hang.  Execution
       of some infected programs will result in an I/O error and the program
       aborting execution.  The DOS Directory command may also not function
       properly.  Lastly, infected systems may experience frequent system
       hangs requiring the user to reboot the system.

       Also see: Do-Nothing


 Virus Name:  Saratoga
 Aliases:     642, One In Two
 V Status:    Extinct
 Discovery:   July, 1989
 Symptoms:    .EXE growth, Resident, bad sectors, FAT corruption
 Origin:      California, USA
 Eff Length:  642 Bytes
 Type Code:   PRsE - Resident Parasitic .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan 1.4+, VirexPC,
              VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, F-Prot, VirexPC, Pro-Scan 1.4+, VirexPC 1.1B+,
              VirHunt 2.0+, NAV, or delete infected files
 General Comments:
       The Saratoga Virus was first isolated in California in July 1989.
       This virus is very similar to the Icelandic and Icelandic-II
       viruses, so only the differences from the Icelandic viruses
       are indicated here.  Please refer back to the description of
       the Icelandic virus for the base information.

       The Saratoga virus's main difference from the Icelandic virus
       is that when it copies itself to memory, it modifies the memory
       block so that it appears to belong to the operating system,
       thus avoiding another program reusing the block.

       Similar to the Icelandic-II virus, the Saratoga can infect
       programs even if the system has installed an anti-viral TSR
       which "hooks" interrupt 21, such as FluShot+.  Also like
       Icelandic-II is that this virus can infect programs which have
       been marked Read-Only, though it does not restore the Read-Only
       attribute to the file afterwards.

       Also see: Icelandic, Icelandic-II


 Virus Name:  Saturday The 14TH
 Aliases:     Durban
 V Status:    Rare
 Discovered:  March, 1990
 Symptoms:    TSR;.COM, .EXE, .OV? growth; corrupts boot sector,
              FAT. & partition table on Saturday 14th
 Origin:      Republic of South Africa
 Eff Length:  685 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V61+, Pro-Scan 1.4+, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, VirHunt 2.0+, Pro-Scan 2.01+
 General Comments:
       The first reports of the Saturday The 14TH virus came from
       South Africa in March 1990.  The Saturday The 14TH, or Durban
       Virus, is a memory resident generic file infector, infecting
       .COM, .EXE, and overlay files, but not COMMAND.COM.  Infected
       files will increase in length by between 669 and 684 bytes.

       The Saturday The 14TH virus activates on any Saturday that falls
       on the 14TH of any month, at which time it will overwrite the
       first 100 logical sectors of the C: drive, B: drive, and A:
       drive.  In effect, on drive C:, the virus destroys the hard
       disk boot sector, partition table, and file allocation table (FAT).


 Virus Name:  Scott's Valley
 Aliases:     2131, Slow-2131
 V Status:    Rare
 Discovered:  September, 1990
 Symptoms:    TSR; .COM and .EXE growth
 Origin:      Scott's Valley, California, USA
 Eff Length:  2,131 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The Scott's Valley Virus was discovered in September, 1990 in
       Scott's Valley, California.  This virus is a memory resident generic
       infector of .COM and .EXE files, and does not infect COMMAND.COM.

       The first time a program infected with the Scott's Valley Virus is
       executed, the virus installs itself memory resident as a low system
       memory TSR of 2,384 bytes.  Interrupt 21 is hooked by the virus.

       After the virus is memory resident, any .COM or .EXE file executed
       will be infected with the virus.  .COM files will increase in length
       by 2,131 bytes.  .EXE files will increase in length between 2,131
       and 2,140 bytes.

       Infected programs will contain the following hex string in the virus's
       code: 5E8BDE909081C63200B912082E.

       It is unknown if this virus is malicious.


 Virus Name:  Sentinel
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM & .EXE growth; decrease in available free memory
 Origin:      Bulgaria
 Eff Length:  4,625 Bytes
 Type Code:   PRHAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Sentinel Virus was submitted in January, 1991, and is from
       Bulgaria.  This virus is a memory resident infector of .COM and .EXE
       files, and will infect COMMAND.COM.  Unlike most viruses, this virus
       was received with its original Turbo Pascal source code.  It may be
       purely a research virus at this time.

       When the first program infected with Sentinel is executed, the virus
       will install itself memory resident at the top of system memory, but
       below the 640K DOS boundary.  Interrupt 12's return is not moved by
       the virus.  Interrupt 21 will be hooked by the virus in memory.
       COMMAND.COM, if not previously infected, will be infected by Sentinel
       at this time as well.

       After Sentinel is memory resident, it will infect .COM and .EXE
       programs larger than 1K as they are openned or executed.  Infected
       programs will have a file length increase of 4,625 bytes, the virus
       will be located at the end of the file.  This virus makes no attempt
       to hide the file length increase.  File date and time in the disk
       directory is not altered by the virus.

       The following text strings can be found at the very end of programs
       infected with Sentinel:

               "You won't hear me, but you'll feel me....
                (c) 1990 by Sentinel.
                With thanks to Borland."

       Sentinel does not appear to do anything besides replicate.


 Virus Name:  SF Virus
 Aliases:
 V Status:    Extinct
 Discovered:  December, 1987
 Symptoms:    BSC 360k floppies, Resident TOM, formatted disks
 Origin:      California, USA
 Eff Length:  N/A
 Type Code:   RtF - Resident Floppy Boot Sector Infector
 Detection Method: ViruScan (identifies as Alameda)
 Removal Instructions: MDisk, CleanUp, F-Prot, or DOS SYS command
 General Comments:
       The SF Virus is a modified version of the Alameda virus
       which activates when the counter in the virus has determined
       that it is infected 100 diskettes.  The virus replicates when
       a CTL-ALT-DEL is performed, infecting the disk in the floppy
       drive.  Upon activation, the diskette in the floppy drive is
       reformatted.  The SF Virus only infects 5 1/4" 360K floppies.

       Also see: Alameda


 Virus Name:  Shake Virus
 Aliases:
 V Status:    Rare
 Discovered:  May, 1990
 Symptoms:    .COM growth, message, change in COMMAND.COM memory allocation
 Origin:      Bulgaria
 Eff Length:  476 Bytes
 Type Code:   PRCK - Resident Parasitic .COM Infector
 Detection Method: ViruScan V63+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+,
              VirHunt 2.0+, NAV
 Removal Instructions: Scan/D, Pro-Scan 2.01+, or Delete Infected Files
 General Comments:
       The Shake Virus was first isolated in Bulgaria in May, 1990 by
       Daniel Kalchev.  It is a memory resident generic .COM infector, and
       will infect COMMAND.COM.

       The first time an infected program is executed, the Shake Virus will
       install itself memory resident, altering the image of COMMAND.COM in
       memory.

       The Shake Virus infects .COM files, infecting them as they are
       accessed.  Infected files increase in size by 476 Bytes, though the
       size increase cannot be seen using a DIR (list directory) command
       if the virus is memory resident.

       While the virus is not destructive, it will occasionally
       display the message: "Shake well before use !" when an infected
       file is attempted to be run.  When this message is displayed, the
       program terminates rather than executes.  A second attempt to run
       the same program result in it running successfully.


 Virus Name:  Slayer Family
 Aliases:     Brain Slayer, Slayer, Yankee Doodle Dropper
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM & .EXE growth; Long disk accesses; Disk directory altered;
              Disk accesses to unexpected drives
 Origin:      USA
 Eff Length:  5,120 Bytes
 Type Code:   PNA - Resident Non-Parasitic .COM & .EXE Infector
 Detection Method: ViruScan V76+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Slayer Family of Viruses was discovered in March, 1991.  This
       group of viruses currently consists of five known variants which were
       submitted from different locations at approximately the same time.  All
       of the variants are non-resident direct action infectors of .COM and
       .EXE files.  They do not infect COMMAND.COM.

       Below is a generic description of the viruses in this family.  Specifics
       for each variant are listed under "Known variants" at the end of this
       entry.  In some cases, the only difference between the variants is a
       few bytes.

       When a program infected with a Slayer Family virus is executed, it will
       infect all .COM and .EXE programs in the current directory on the
       current drive.  Additionally, depending on the variant, it may infect
       some programs on other drives as well.

       Programs infected with a Slayer Family virus will increase in size
       between 5,120 and 5,135 bytes with the virus being located at the end
       of the infected file.  The program's date and time in the disk directory
       will not be altered.

       Symptoms of Slayer Family viruses include long disk accesses when
       attempting to execute an infected program, and possibly disk accesses
       to unexpected drives.  The order of the disk directory on infected
       systems may also be altered so that .COM programs appear first in the
       directory.

       At least one member of this family, Slayer-E or Yankee Doodle Dropper,
       carries the Yankee Doodle Virus which it will later release on infected
       systems.  This Yankee Doodle is the TP45VIR variant.

       Known variant(s) of Slayer include:
       Slayer-A : Slayer-A will infect up to nine programs in a directory,
                  other than the root directory, on the system C: drive in
                  addition to programs on the current drive when an infected
                  program is executed.
       Slayer-B : Similar to Slayer-A, this variant will infect programs
                  located in the C: drive root directory in addition to those
                  located on the current drive and directory.
       Slayer-C : Similar to Slayer-A and Slayer-B, Slayer-C will infect all
                  programs located on the current drive and all programs
                  located on the C: drive.  The following text strings can be
                  found in samples of Slayer-C:
                  "KEYB*.COM KEYB*.EXE BASRUN BRUN COBRUN NET$OS *.COM"
                  "IBMBIO.COM"
                  "IBMDOS.COM COMMAND.COM *.* .. \ .. *.EXE"
                  "Access denied."
       Slayer-D : Slayer-D is similar to Slayer-C, the major difference being
                  that while it accesses the C: drive when an infected program
                  is executed, it will not infect any programs on the C: drive
                  unless the infected program was being executed from C:.
                  The text strings indicated for Slayer-C also occur for this
                  variant.
       Slayer-E : Slayer-E is also known as the Yankee Doodle Dropper.  When
                  an infected program is executed, it will infect all the
                  programs on the current drive and directory, and then infect
                  a few programs on the C: drive.  After some period of time
                  has elasped since the original infection, this variant will
                  release the Yankee Doodle Virus onto the system, resulting
                  in an active Yankee Doodle infection.  If the system user
                  successfully removes Yankee Doodle, but doesn't remove the
                  Slayer-E infection, Yankee Doodle will promptly reinfect the
                  system from the Slayer-E infected programs which remain.
                  This variant is known to be in the public domain.


 Virus Name:  Slow
 Aliases:     Slowdown
 V Status:    Common
 Discovered:  May, 1990
 Symptoms:    .COM & .EXE growth
 Origin:      Australia
 Eff Length:  1,701 Bytes
 Type Code:   PRsA - Resident Parasitic .COM & .EXE Infector
 Detection Method: ViruScan V63+, Pro-Scan 1.4+, NAV
 Removal Instructions: CleanUp V67+, Scan/D, Pro-Scan 2.01+, NAV
 General Comments:
       The Slow Virus was discovered in Australia in May 1990.  It is
       a memory resident generic file infector, infected .COM, .EXE, and
       overlay files.  COMMAND.COM is not infected by this virus.

       The first time an infected file is executed on a system, the virus
       installs itself memory resident as a low system memory TSR, taking up
       1,984 bytes of free memory.  Interrupt 21 will be hooked by the virus.

       Later, as programs are executed, they will be infected by the Slow
       Virus.  While the Slow Virus's viral code is actually 1,701 bytes in
       length, infected files will increase by more than this amount.  Infected
       .COM files will increase in length by 1,721 bytes with the virus
       located at the beginning of the infected program.  .EXE files will
       increase in length by 1,716 to 1,728 bytes with the virus located at
       the end of the infected program.

       In the process of infecting some .EXE files, the virus may hang the
       system, causing the user to have to reboot.

       The Slow Virus is based on the Jerusalem B virus.

       It is unknown what else the Slow virus does.


 Virus Name:  Smack
 Aliases:
 V Status:    New
 Discovered:  May, 1991
 Symptoms:    .COM & .EXE growth; Decrease in total system & available memory;
              Programs and/or Data files may disappear; Messages on Fridays;
              Lost clusters
 Origin:      Italy
 Eff Length:  1,835 Bytes
 Type Code:   PRhA - Resident Parasitic .COM & .EXE Infector
 Detection Method:
 Removal Instructions: Delete Infected Files
 General Comments:
       The Smack Virus was submitted in May, 1991.  It is from Italy.  This
       virus is based on the Migram Virus, and infects .COM & .EXE files, but
       not COMMAND.COM.

       The first time a program infected with Smack is executed, Smack will
       install itself memory resident at the top of system memory but below
       the 640K DOS boundary.  Interrupt 21 will be hooked by the virus.
       Total system memory and available free memory, as measured by the DOS
       ChkDsk program, will have decreased by 1,856 bytes.

       After becoming memory resident, Smack will infect .COM and .EXE programs
       over 3K in length when they are executed.  Infected programs will
       increase in size by 1,835 bytes, the virus being located at the end of
       infected files.  The program's date and time in the disk directory
       will not be altered.

       Systems infected with Smack will experience the occassional
       disappearance of both programs and data files when infected programs
       are executed.  When these erasures of programs and data files occur,
       they are removed from the beginning of the current directory.  If the
       current directory contained COMMAND.COM as the first entry, it will be
       erased.  Needless to say, the removal of COMMAND.COM will result in
       problems whenever DOS attempts to reload it, or the user attempts to
       boot the system.  Infected systems will also notice a gradual increase
       in lost clusters on the system hard disk and floppies.

       Smack activates on Fridays when infected .EXE programs are executed.
       When an infected .EXE program is executed, Smack may display the
       following message:

               "Is today Friday? (Y/N)"

       Replying "Y" will result in the following message and the program
       being terminated:

               "Sorry but on Friday I wish not work!!"

       Replying "N" will result in the following message, though the
       threatened FAT damage does not occur due to a bug in the virus:

               "You are untruthful!! For punishment I format your HD FAT!!"

       Other text strings located in the Smack Virus are:

               "This virus was written in Italy by Cracker Jack 1991 IVRL"
               "All rights reserved, please don't crack this virus!!"
               "Special message to Patricia Hoffman: I love you!!!!!!!!"
               "SmackSmack"
               "Can you give me your telephone number??? Ciao bellissima!"

       Needless to say, the author of this listing had nothing to do with the
       creation of this virus.

       Also see: Migram


 Virus Name:  Solano 2000
 Aliases:     Dyslexia 2.01, Solano
 V Status:    Rare
 Discovered:  March, 1990
 Symptoms:    .COM growth, TSR, unusual file errors
 Origin:      California, USA
 Eff Length:  2,000 Bytes
 Type Code:   PRsC - Resident Parasitic .COM Infector
 Detection Method: ViruScan V60+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 2.01+, or Delete Infected Files
 General Comments:
       The Solano 2000 Virus was first isolated in Solano County,
       California in mid-March 1990 by Edward Winters.  The virus may
       also be known by the name Dyslexia Virus V2.01, which can be
       produced by negating some null terminated bytes within the
       viral code.  Using the same technique, what appears to be the
       creation date of the virus, 08FEB90, can be produced.  The
       information regarding the information produced by negation of
       bytes was determined by Jay Parangalan of Solano County.

       The Solano 2000 Virus is a generic .COM file infector.  The first
       time an infected .COM file is executed on the system, the virus
       installs itself memory resident, then proceeds to infect every
       .COM file that is executed.  Infected programs can be manually
       identified by using a sector editor to view the file.  Bytes
       1168 thru 1952 will consist of '(' or 28h characters.

       Some programs, such as DiskCopy.COM which is included on all
       DOS diskettes, will not run after being infected with this virus,
       instead an "invalid drive specification" message will be
       displayed.  This message is not in the viral code, but is due
       to an error condition being induced due to the virus's presence.
       The virus-induced error occurring with the DiskCopy program was how
       the virus was first spotted and eventually isolated.

       This particular virus, in its current state, does not survive a
       system warm reboot (CTL-ALT-DEL).  When it is memory resident, it
       takes up 3K bytes of RAM.

       The Solano 2000 Virus does no apparent system damage, however it
       does check the video buffer occasionally, and may transpose
       numbers if they are found in certain locations.  This effect,
       however, was not experienced on the author's system in researching
       this virus.  There have also been reports that instead of transposing
       numeric characters, the Solano virus may change color attributes on
       the display screen when it is active in memory.

       Known variants of the Solano 2000 virus:
       Solano 2000-B: same as Solano 2000, except the 28h characters
             have been changed to DAh characters, and are located in
             bytes 1168 thru 1912 in infected files.
       Dyslexia 2.00: same as Solano 2000, except that the 28h characters
             are now binary zeros.  The attempted transposing of numeric
             characters in video memory has also been slowed down.  The
             creation date appears to be 22JAN90 instead of 08FEB90.

       Also see: Subliminal 1.10


 Virus Name:  Sorry
 Aliases:     G-Virus V1.3
 V Status:    Rare
 Discovered:  June, 1990
 Symptoms:    .COM growth, decrease in system and free memory
 Origin:
 Eff Length:  731 Bytes
 Type Code:   PRNCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V64+, F-Prot, Pro-Scan 2.01+, NAV
 Removal Instructions:  Scan/D, Pro-Scan 2.01+, NAV, or delete infected files
 General Comments:
       The Sorry Virus was isolated in June, 1990.  Its name comes from
       a german phrase in the virus: "Tut mir Leid !".  This
       virus is based on the Perfume Virus from West Germany, and some
       anti-viral programs will identify it as Perfume or 4711.

       The first time a program infected with the Sorry Virus is executed,
       the virus will install itself memory resident in high memory.  Total
       system memory and free memory will both decrease by 1,024 bytes.
       Interrupt 21 will be hooked by the virus.  COMMAND.COM is immediately
       infected by the virus, thus insuring on later system boots that the
       virus becomes memory resident immediately.

       After the virus is memory resident, it will infect any .COM file
       which is executed, increasing the file's length by 731 bytes.  The
       viral code is located at the end of infected files.

       The Sorry Virus contains the following text strings:

                "G-VIRUS V1.3"
                "Bitte gebe den G-Virus Code ein"
                "Tut mir Leid !"

       It is unknown what the Sorry Virus does when it activates.

       Also see: Perfume


 Virus Name:  Sparse
 Aliases:
 V Status:    Rare
 Discovered:  April, 1991
 Symptoms:    TSR; .COM growth
 Origin:      Unknown
 Eff Length:  3,840 Bytes
 Type Code:   PRsCK - Parasitic Resident .COM Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The Sparse Virus was received in April, 1991.  Sparse is a memory
       resident infector of .COM files, including COMMAND.COM.

       The first time a program infected with Sparse is executed, the virus
       will install itself memory resident as a low system memory TSR of
       3,872 bytes.  Interrupts 21, D1 and D3 will be hooked by the virus.

       Once Sparse is memory resident, it will infect .COM programs, including
       COMMAND.COM, when they are executed.  Infected .COM programs will
       increase in size by 3,840 bytes with the virus being located at the
       beginning of the infected file.  The infected file's date and time in
       the disk directory will also be updated to the system date and time
       when infection occurred.

       Programs infected with Sparse will have the ASCII characters "UK" as
       the second and third bytes of the executable program.  They will also
       contain the text string SHELLC, and contain the name of the program
       that originally resulted in the virus becoming memory resident.  (If
       the first infected program executed was "sparse.com", then "sparse.com"
       will be found in all later infected programs as long as the virus was
       memory resident.)

       It is not known if Sparse does anything besides replicate.


 Virus Name:  Spyer
 Aliases:
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    TSR; .COM & .EXE growth; system hangs
 Origin:      Taiwan
 Eff Length:  1,181 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V71+
 Removal Instructions: Scan/D or Delete infected files
 General Comments:
       The Spyer Virus was isolated in November, 1990 in Taiwan.  This virus
       is a memory resident infector of .COM and .EXE files.  It does not
       infect COMMAND.COM.

       The first time a program infected with the Spyer Virus is executed,
       the Spyer Virus will install itself memory resident as a 1,760 byte
       low system memory TSR.  Interrupts 21 and 22 will be hooked by the
       virus.

       Once the virus is memory resident, the virus will attempt to infect
       the next program that is executed.  If the program is already infected
       with the Spyer Virus, the system will become hung.  If the program was
       not already infected, Spyer will infect it and then hang the system.

       Infected .COM files will always increase in length by 1,181 bytes.
       .EXE files infected with Spyer will have a file length increase between
       1,181 and 1,195 bytes.  In both cases, the virus will be located at
       the end of the infected file.  Infected files will also always have the
       following hex character sequence at the end of file: "CBDFD9DE848484".

       The Spyer Virus, in its present form, is not expected to ever be a
       serious problem.  Since it always hangs the system when the next program
       is executed after becoming memory resident, it is simply too obvious
       that something is wrong.


 Virus Name:  Staf
 Aliases:     Staff
 V Status:    Rare
 Discovered:  April, 1991
 Symptoms:    .COM growth; Messages; Programs may fail to execute
 Origin:      Unknown
 Eff Length:  2,083 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V76+, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Staf Virus was received in April, 1991.  Its origin is unknown, but
       first reports of it were out of Europe.  This virus is a non-resident
       direct action .COM file infector.  It will infect COMMAND.COM.

       When a program infected with the Staf Virus is executed, the virus will
       display the following message:

               "This program has been infected by:

                Virus Demo Ver.: 1.1 - Handle with care!
                By STAF (Tel.: [phone])
                Generation #n

                Infecting: xxxxxxxx.COM

                Press any key to execute original program..."

       The "n" following the pound sign above will be replaced with the
       generation number of the virus.  The "xxxxxxxx.COM" will contain the
       name of the .COM program in the current directory which the virus has
       just infected.  If no uninfected .COM file existed in the current
       directory when an infected program is executed, the "Infecting:"
       portion of the message will be replaced with:

               "I have infected all your files in the current directory!
                Have a nice day!"

       Programs infected with Staf may also fail to execute, with the
       following message being displayed:

               "VIRUS ERROR #nn - Aborting process."

       Programs infected with Staf have a file size increase of 2,083 bytes
       with the virus being located at the beginning of the infected file.
       The virus does not alter the file date and time in the disk directory
       at the time a program is infected.

       Staf does not do anything besides replicate.


 Virus Name:  StarDot 600
 Aliases:
 V Status:    Rare
 Discovered:  April, 1991
 Symptoms:    .EXE growth
 Origin:      Unknown
 Eff Length:  600 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The StarDot 600 Virus was submitted in April, 1991.  Its origin is
       unknown.  This virus is a non-resident infector of .EXE programs.

       When a program infected with StarDot 600 is executed, StarDot 600 will
       infect one .EXE program in the current directory.  Programs infected
       with StarDot 600 will increase in length by 604 to 616 bytes with the
       virus being located at the end of the newly infected file.  The file's
       date and time in the disk directory will not be altered.

       StarDot 600 does not do anything besides replicate.


 Virus Name:  StarDot 801
 Aliases:
 V Status:    Rare
 Discovered:  April, 1991
 Symptoms:    .COM & .EXE growth; System hangs
 Origin:      Unknown
 Eff Length:  801 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The StarDot 801 Virus was submitted in April, 1991.  Its origin is
       unknown, though it is very similar to the Italian 803 virus, so it
       may also be from Italy.  StarDot 801 is a non-resident, direct action
       infector of .COM and .EXE programs.  It will infect COMMAND.COM.

       When a program infected with StarDot 801 is executed, the virus will
       look for an uninfected .EXE program in the current directory to infect.
       If an uninfected .EXE program does not exist in the current directory,
       it will then look for an uninfected .COM program to infect.  Once an
       uninfected program is selected, the virus will infect it, adding the
       viral code to the end of the program.

       Programs infected with StarDot 801 will increase in size by 804 to
       817 bytes.  Their date and time in the disk directory will not be
       altered.

       StarDot 801 does not appear to do anything besides replicate.  System
       hangs, however, may occur when some infected programs are executed.


 Virus Name:  Stone`90
 Aliases:     Polish 961, Stone-90
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth
 Origin:      Poland
 Eff Length:  961 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Stone`90 Virus, or Polish 961, is a non-resident direct action
       infector of .COM programs, including COMMAND.COM.  It was submitted
       in December, 1990, and is from Poland.

       When a program infected with the Stone`90 Virus is executed, the virus
       will look for one .COM program on the current drive and in the current
       directory to infect.  If one is found, the virus will infected it.
       The newly infected .COM program will increase in length by 961 bytes,
       and have the virus's code located at the end of the program.

       The following text strings can be found in infected files:

               "Sorry, I`m INFECTED!"
               "I`m already NOT infected!"
               "(C) Stone`90"

       Stone`90 does not appear to do anything besides replicate.


 Virus Name:  Stoned
 Aliases:     Donald Duck, Hawaii, Marijuana, New Zealand, Rostov, San Diego,
              Sex Revolution, Smithsonian, Stoned II
 V Status:    Common
 Discovered:  February, 1988
 Symptoms:    BSC, TSR, messages, RLL controller hangs
 Origin:      New Zealand
 Eff Length:  N/A
 Type Code:   BRtX - Resident Boot Sector & Partition Table Infector
 Detection Method:  ViruScan, CleanUp, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  CleanUp, MDisk, F-Prot, Pro-Scan 1.4+, NAV
 General Comments:
       The Stoned virus was first reported in Wellington, New Zealand in
       early 1988.  The original virus only infected 360KB 5 1/4" diskettes,
       doing no overt damage.  The original diskette-only infector is extinct,
       however, and all known variants of this virus are capable of infecting
       the hard disk partition table as well as may damage directory or FAT
       information.  Most variants of this virus have only minor modifications,
       usually in what the message is that the virus may display on boot.

       When a computer system is booted with a Stoned infected disk, this
       virus will install itself memory resident at the top of system memory.
       The interrupt 12 return will be moved, and ChkDsk will indicate that the
       computer system as 2K less total memory than what is installed.  If the
       system boot was from a diskette, the virus will also attempt to infect
       the hard disk partition table, if it was not previously infected.

       During the boot process, the Stoned Virus may display a message.  The
       message is displayed more or less on a random basis.  The most common
       text for the message is:

               "Your computer is now stoned."

       Or:

               "Your PC is now Stoned!"

       After Stoned is memory resident, it will infect diskettes as they are
       accessed on the system.  When Stoned infects a diskette, it moves the
       original boot sector (sector 0) to sector 11.  The Stoned Virus then
       copies itself into sector 0.  Since sector 11 is normally part of the
       diskette root directory on 360K 5.25" diskettes, any files which had
       their directory entries located in this sector will be lost.  Some
       versions of DOS have sector 11 as part of the File Allocation Table,
       which may also result in the disk's FAT being corrupted.

       When Stoned infects that system hard disk, it copies the hard disk's
       original partition table to side 0, cyl 0, sector 7.  A copy of the
       Stoned Virus is then placed at side 0, cyl 0, sector 1, the original
       location of the hard disk partition table.  If the hard disk was
       formatted with software which starts the boot sector, file allocation
       table, or disk directory on side 0, cyl 0 right after the partition
       table, the hard disk may be corrupted as well.

       In order to disinfect a system infected with the Stoned Virus, the
       system must be powered off and booted with an uninfected, write-
       protected boot diskette.  If this is not done, the virus may reinfect
       diskettes as soon as they are disinfected.

       There are many programs which can disinfect Stoned infected diskettes
       and hard disks.  To successfully use one of these, follow the
       instructions with the program.

       To remove Stoned manually, the DOS SYS command can be used on 5.25"
       360K diskettes.  On the hard disk, the original partition table must
       be copied back to side 0, cyl 0, sector 1.  This can be performed with
       Norton Utilities, or other sector editors.

       Known variants of the Stoned Virus are:
       Stoned-A : Same as Stoned above, but does not infect the system hard
                  disk.  This is the original virus and is now extinct.  The
                  text found in the boot sector of infected diskettes is:
                  "Your computer is now stoned.  Legalize Marijuana".
                  The "Legalize Marijuana" portion of the text is not
                  displayed.
       Stoned-B : Same as Stoned indicated above.  Systems with RLL controllers
                  may experience frequent system hangs.  Text typically found
                  in this variant is:
                  "Your computer is now stoned.  Legalise Marijuana".
                  The "Legalise Marijuana" may also be in capital letters, or
                  may be partially overwritten.  It is not displayed.
       Stoned-C : same as Stoned, except that the message has been
                  removed.
       Stoned-D : same as Stoned, with the exception that this variant
                  can infect high density 3.5" and 5.25" diskettes.
       Stoned II: Based on Stoned-B, this variant has been modified to
                  avoid detection by anti-viral utilities.  Since its
                  isolation in June, 1990, most utilities can now detect
                  this variant.  Text in the virus has been changed to:
                  "Your PC is now Stoned!  Version 2"
                  Or:
                  "Donald Duck is a lie."
                  The "Version 2" portion of the text may be corrupted as well.

       Rostov   : Similar to Stoned-B, this variant does not display any
                  message.  It contains the text:
                  "Non-system disk" and "Replace and strike".
                  Submitted in December, 1990, origin unknown.
       Sex Revolution V1.1 :
                  Submitted in December, 1990, this variant is similar to
                  Stoned-B.  This variant may display the following message:
                  "EXPORT OF SEX REVOLUTION ver. 1.1"
       Sex Revolution V2.0 :
                  Similar to Sex Revolution V1.1, the message has been changed
                  to:
                  "EXPORT OF SEX REVOLUTION ver. 2.0"
       Stoned-E : Similar to Stoned-B, this variant now emits a "beep" thru
                  the system speaker when the following message is displayed:
                  "Your PC is now Stoned!"
                  The text "LEGALISE MARIJUANA!" can also be found in the
                  boot sector and system partition table.
       Stoned-F : Similar to Stoned-E, this variant also emits a "beep" thru
                  the system speaker when its message is displayed.  The
                  displayed message is:
                  "Twoj PC jest teraz be!"
                  The text "LEGALISE MARIJUANA?" can also be found in the
                  boot sector and system partition table.
       PS-Stoned: Based on the Stoned Virus, PS-Stoned is a variant which has
                  been altered to avoid detection.  Unlike most members of the
                  Stoned Family, PS-Stoned does not contain a message, and does
                  not display any message when the system is booted from an
                  infected disk.  This variant will infect the boot sector
                  of both normal and high-density diskettes, as well as the
                  hard disk partition table.  In the case of the partition
                  table, the original partition table is moved to cylinder 0,
                  side 0, sector 17.  On low density diskettes, the original
                  boot sector is moved to sector 11, while on high density
                  diskettes it can be found at sector 16.  This variant was
                  originally received in February, 1991, from New Brunswick,
                  Canada after being isolated at a university.  As of May,
                  1991, no anti-viral products detect this variant which can
                  be just about invisible on infected systems.

       Also see:  Evil Empire-A


 Virus Name:  Striker #1
 Aliases:
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM growth
 Origin:      United States
 Eff Length:  461 Bytes
 Type Code:   PNC - Non-Resident Parasitic .COM Infector
 Detection Method: ViruScan V76+
 Removal Instructions: CleanUp V77+, or Delete Infected Files
 General Comments:
       The Striker #1 Virus was isolated in the Eastern United States in
       March, 1991.  This virus is a non-resident, direct action infector of
       .COM programs, including COMMAND.COM.

       When a program infected with Striker #1 is executed, the virus will
       infect one .COM program.  Infected .COM programs will have the first
       thirteen bytes altered, and then the body of the virus appended to the
       end of the program.  Infected programs will show a file length increase
       of 461 bytes in the disk directory, file date and times are not altered.

       Infected programs can be easily identified as the text string
       "Striker #1" will appear in the fourth thru thirteenth bytes of all
       infected programs.  This string also appears near the end of infected
       programs.

       Striker #1 does not appear to do anything besides replicate.


 Virus Name:  Subliminal 1.10
 Aliases:
 V Status:    Rare
 Discovered:  May, 1990
 Symptoms:    .COM growth, TSR, unusual file errors, video display flicker
 Origin:      California, USA
 Eff Length:  1,496 Bytes
 Type Code:   PRsC - Resident Parasitic .COM Infector
 Detection Method: ViruScan V64+, Pro-Scan 1.4+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 1.4+, or Delete Infected Files
 General Comments:
       The Subliminal 1.10 Virus was first isolated in Solano County,
       California in May 1990 by Jay Parangalan.  The name of the
       virus can be produced by negating (XORing with FF) some null
       terminated bytes in the viral code.  Using this technique, the
       creation date of the virus appears to be 02OCT89.  The
       Subliminal 1.10 Virus appears to be a very early version of the
       Solano 2000 Virus, and has only been reported at Solano
       Community College.

       The first time a program infected with the Subliminal 1.10 Virus
       is executed, the virus installs itself memory resident.  Any
       .COM files which are then executed are infected.  Infected
       programs will increase in length by 1,496 bytes.

       With the virus memory resident, the system monitor will appear to
       flicker.  What is occurring is that the virus is attempting to
       flash the message "LOVE, REMEMBER?" in the lower left portion of
       the display for a subliminal duration.  The actual amount of time
       the message displays on the screen varies between systems due to
       CPU speed.

       Also see: Solano 2000


 Virus Name:  Sunday
 Aliases:
 V Status:    Common
 Discovered:  November, 1989
 Symptoms:    TSR, executable file growth, messages, FAT corruption
 Origin:      Washington (state), USA
 Eff Length:  1,636 Bytes
 Type Code:   PRsAT - Parasitic Resident .COM, .EXE. & .OV? Infector
 Detection Method:  ViruScan V49+, F-Prot, IBM Scan, Pro-Scan, VirexPC 1.1+,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: CleanUp, Scan/D, F-Prot, Pro-Scan 1.4+, VirexPC,
              VirHunt 2.0+, NAV
 General Comments:
       The Sunday virus was discovered by many users in the Seattle,
       Washington area in November, 1989.  This virus activates on
       any Sunday, displaying the message:

           "Today is Sunday! Why do you work so hard?
            All work and no play make you a dull boy!
            Come on! Let's go out and have some fun!"

       The Sunday virus appears to have been derived from the
       Jerusalem virus, the viral code being similar in many
       respects.

       Damage to the file allocation table or FAT has been reported
       from a number of infected users.

       Known variants of the Sunday Virus are:
       Sunday-B : Similar to the Sunday Virus, this variant does not activate
                  on any day of the week due to an error in the day of the
                  week checking routine.  The message in the virus is never
                  displayed, and no damage is done to the file allocation
                  table.
       Sunday-C : Similar to Sunday-B, this variant also never activates.  It
                  has, however, been modified so that it differs from both
                  the Sunday and Sunday-B viruses.  Functionally, it is the
                  same as Sunday-B.


 Virus Name:  Suriv 1.01
 Aliases:     April 1st, Israeli, Suriv01
 V Status:    Extinct
 Discovered:  April, 1987
 Symptoms:    TSR, .COM growth, messages, system lock April 1st
 Origin:      Israel
 Eff Length:  897 bytes
 Type Code:   PRsC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  Scan/D/X, F-Prot, VirHunt 2.0+, or UnVirus
 General Comments:
       The Suriv 1.01 virus is a memory resident .COM infector.  It
       will activate on April 1st after memory is infected by running
       an infected file and then a uninfected .COM file is executed.
       On activation, it will display the message:

       "APRIL 1ST HA HA HA YOU HAVE A VIRUS".

       The system will then lock up, requiring it to be powered off and
       then back on.

       The text "sURIV 1.01" can be found in the viral code.


 Virus Name:  Suriv 2.01
 Aliases:     April 1st-B, Israeli, Suriv02
 V Status:    Extinct
 Discovered:  1987
 Symptoms:    TSR, .EXE growth, messages, system lock April 1st
 Origin:      Israel
 Eff Length:  1,488 bytes
 Type Code:   PRsE - Parasitic Resident .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, VirexPC, Pro-Scan,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  Scan/D/X, F-Prot, UnVirus, VirHunt 2.0+
 General Comments:
       The Suriv 2.01 virus is a memory resident .EXE infector.  It
       will activate on April 1st after memory is infected by running
       an infected file, displaying the same message as Suriv 1.01
       and locking up the system.  The virus will cause a similar
       lockup, though no message, 1 hour after an infected .EXE file
       is executed on any day on which the system default date of
       01-01-80 is used.  The virus will only infect the file once.


 Virus Name:  Suriv 3.00
 Aliases:     Israeli, Suriv03
 V Status:    Extinct
 Discovered:  1988
 Symptoms:    TSR, .COM, .EXE, & .SYS growth; Black Window; system slowdown
 Origin:      Israel
 Eff Length:  1,813 (COM files) & 1,808 (EXE files) bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: CleanUp, Scan/D/X, F-Prot, Unvirus, VirHunt 2.0+
 General Comments:
       May be a variant of the Jerusalem virus.  The string "sUMsDos"
       has been changed to "sURIV 3.00".  The Suriv 3.00 virus
       activates on Friday The 13ths when an infected program is
       run or if it is already present in system memory, however
       files are not deleted due to a bug in the viral code.

       Other than on Friday The 13ths, after the virus is memory
       resident for 30 seconds, an area of the screen is turned into
       a "black window" and a time wasting loop is executed with
       each timer interrupt.

       As with the Jerusalem B viruses, this virus can also infect
       overlay, .SYS, and other executable files besides .EXE and
       .COM files, though it does not infect COMMAND.COM itself.

       Also see: Jerusalem, Jerusalem B


 Virus Name:  Sverdlov
 Aliases:     Hymn-2
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM & .EXE growth; decrease in total system and available memory
 Origin:      USSR
 Eff Length:  1,962 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected programs
 General Comments:
       The Sverdlov Virus was submitted in December, 1990.  This virus is
       believed to have originated in the USSR.  Sverdlov is a memory resident
       infector of .COM and .EXE files, and will infect COMMAND.COM.  This
       virus is also encrypted.

       The first time a program infected with the Sverdlov Virus is executed,
       the virus will install itself memory resident at the top of system
       memory but below the DOS 640K boundary.  4,080 bytes of memory will
       have been reserved, and the interrupt 12 return is not altered by the
       virus.  The DOS ChkDsk program will indicate that total system memory
       and available free memory is 4,080 bytes less than expected.
       COMMAND.COM will also be infected at this time if it was not already
       infected.

       Once Sverdlov is memory resident, any .COM or .EXE file over 2K in
       length will become infected if it is executed or openned for any reason.
       Infected .COM files have a file length increase of 1,962 bytes.
       Infected .EXE files will have a file length increase of 1,962 to
       1,977 bytes in length.  In both cases, the virus will be located at the
       end of infected programs.

       It is unknown if Sverdlov does anything besides replicate.

       Known variant(s) of Sverdlov include:
       Sverdlov-B : Very similar to the original Sverdlov Virus, this variant
                    has one basic change in behavior.  It will only infect
                    .COM and .EXE files over 3K in length before infection.
                    Otherwise, the virus code is very similar.  This variant
                    may have been altered to avoid detection, and some
                    anti-viral programs may identify it as Hymn-2.


 Virus Name:  SVir
 Aliases:
 V Status:    Endangered
 Discovered:  1990
 Symptoms:    .EXE growth; file date/time changes; system hangs
 Origin:      Poland
 Eff Length:  512 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method: ViruScan V76+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected programs
 General Comments:
       The SVir Virus was originally isolated in Poland early in 1990.  The
       original virus which was isolated had a fatal flaw in its code which
       prevented it from executing.  In August, 1990, a sample was obtained
       from Fridrik Skulason which now does replicate.  This second sample,
       identified as SVir-B, is a non-resident infector of .EXE files.  A
       third variant was received in April, 1991.

       Each time a program infected with the SVir-B Virus is executed, the
       virus will infect one .EXE file.  Infected files will increase in
       length between 516 and 526 bytes with the virus's code appended to the
       end of the file.  If the virus could not find an .EXE file to infect,
       it will leave the drive "spinning" as it will be in an endless loop
       looking for a file to infect.

       Interestingly enough, this virus will only infect files located on the
       A: drive.

       Infected files will also have their date/time in the disk directory
       changed to the date and time when the infection occurred.

       SVir, at least in the three known variants, does not do anything
       malicious, it simply replicates.

       Known variants of SVir are:
       SVir-A : The original "virus" from Poland in early 1990 which did not
                replicate.
       SVir-B : A variant isolated in August, 1990 which has the bug in SVir-A
                fixed so that it will now replicate.
       SVir-0 : A variant received in April, 1991, this variant is very
                similar to SVir-B.  When an infected program is executed, the
                virus may infect either 1 or 2 previously uninfected .EXE
                files in the current directory.  Execution of some infected
                programs may result in a system hang.


 Virus Name:  Swap
 Aliases:     Falling Letters Boot, Israeli Boot
 V Status:    Rare
 Discovered:  August, 1989
 Symptoms:    Graphic display, BSC (floppy only), TSR, bad cluster,
 Origin:      Israel
 Eff Length:  N/A
 Type Code:   RsF - Resident Floppy Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, VirexPC, VirHunt 2.0+
 Removal Instructions:  MDisk, CleanUp, F-Prot, or DOS SYS Command
 General Comments:
       The Swap Virus, or Israeli Boot Virus, was first reported in
       August 1989.  This virus is a memory resident boot sector
       infector that only infects floppies.  The floppy's boot
       sector is infected the first time it is accessed.  One bad
       cluster will be written on track 39, sectors 6 and 7 with the
       head unspecified.  If track 39, sectors 6 and 7, are not
       empty, the virus will not infect the disk.  Once the virus
       is memory resident, it uses 2K or RAM.  The actual length of
       the viral code is 740 bytes.

       The Swap virus activates after being memory resident for 10
       minutes.  A cascading effect of letters and characters on the
       system monitor is then seen, similar to the cascading effect
       of the Cascade and Traceback viruses.

       The virus was named the Swap virus because the first isolated
       case had the following phrase located at bytes 00B7-00E4 on
       track 39, sector 7:

           "The Swapping-Virus. (C) June, 1989 by the CIA"

       However, this phrase is not found on diskettes which have been
       freshly infected by the Swap virus.

       A diskette infected with the Swap virus can be easily identified
       by looking at the boot sector with a sector editor, such as
       Norton Utilities.  The error messages which normally occur at
       the end of the boot sector will not be there, instead the start
       of the virus code is present.  The remainder of the viral code
       is located on track 39, sectors 6 and 7.


 Virus Name:  Swedish Disaster
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    BSC; Partition Table Altered;
              Decrease in system and available free memory
 Origin:      Sweden
 Eff Length:  N/A
 Type Code:   BRhX - Resident Boot Sector & Partition Table Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: MDisk/P
 General Comments:
       The Swedish Disaster was isolated in January, 1991.  This virus appears
       to be from Sweden.  It is a memory resident infector of floppy boot
       sectors and the hard disk partition table.

       When the system is booted from a diskette whose boot sector is infected
       with the Swedish Disaster Virus, the virus will infect the system
       hard disk's partition table, with the original hard disk partition
       table moved to side 0, cylinder 0, sector 6.  The virus will also
       install itself memory resident at the top of system memory but below
       the 640K DOS boundary.  Total system memory will decrease by 2,048
       bytes, available free memory will be 6,944 bytes less than what is
       expected by the user.  Interrupt 12's return will have been moved by
       the virus.

       After Swedish Disaster is memory resident, the virus will infect all
       non-write protected diskettes which are accessed on the system.  On
       360K 5.25" diskettes, the original boot sector will have been moved
       to sector 11, which is normally a part of the root directory.  This
       means that if the disk originally had directory entries in that sector,
       they will be lost.

       The following text string can be found at the end of the boot sector
       of infected diskettes, as well as within the partition table on infected
       hard disks:

               "The Swedish Disaster"

       Diskettes infected with the Swedish Disaster can be disinfected by
       powering off the system and rebooting from a write-protected original
       DOS diskette.  The DOS Sys command can then be used to replace the
       boot sector on infected diskettes.  For hard disks, the MDisk/P program
       will remove this virus, though the above text string will remain in
       the partition table.


 Virus Name:  Swiss 143
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; File date/time changes
 Origin:      Switzerland
 Eff Length:  143 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Swiss 143 Virus was submitted in January, 1991, by Dany Schoch of
       Hagendern, Switzerland.  This virus is a non-memory resident infector
       of .COM files, including COMMAND.COM.

       When a program infected with Swiss 143 is executed, the virus will
       infect all .COM files in the current directory.  Infected programs
       will increase in length by 143 bytes, the virus will be located at the
       end of the infected program.  The disk directory date and time will also
       be altered to the current system date and time when the programs were
       infected.

       This virus does not do anything besides replicate.


 Virus Name:  SysLock
 Aliases:     3551, 3555
 V Status:    Endangered
 Discovered:  November, 1988
 Symptoms:    .COM & .EXE growth, data file corruption
 Origin:
 Eff Length:  3,551 Bytes
 Type Code:   PNA - Encrypting Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan, F-Prot, Pro-Scan, AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D, or F-Prot
 General Comments:
       The SysLock virus is a parasitic encrypting virus which
       infects both .COM and .EXE files, as well as damaging some
       data files on infected systems.  This virus does not install
       itself memory resident, but instead searches through the
       .COM and .EXE files and subdirectories on the current disk,
       picking one executable file at random to infect.  The
       infected file will have its length increased by approximately
       3,551 bytes, though it may vary slightly depending on file
       infected.

       The SysLock virus will damage files by searching for the word
       "Microsoft" in any combination of upper and lower case
       characters, and when found replace the word with "MACROSOFT".

       If the SysLock virus finds that an environment variable
       "SYSLOCK" exists in the system and has been set to "@" (hex 40),
       the virus will not infect any programs or perform string
       replacements, but will instead pass control to its host
       immediately.

       Known variant(s) of SysLock are:
       Advent  : Reported to be a Syslock variant, the sample of this virus
                 received by the author does not replicate.  All known
                 samples of this virus available from anti-viral researchers
                 also do not replicate.  Fridrik Skulason of Iceland has
                 indicated that this virus will only replicate it is on an
                 infected .EXE file, and then it will only infect .COM
                 files.  This variant is thought to be extinct.
       Macho-A : same as the SysLock virus, except that "Microsoft"
                 is replaced with "MACHOSOFT".

       Also see: Cookie

 Virus Name:  Taiwan
 Aliases:     Taiwan 2, Taiwan-B
 V Status:    Endangered
 Discovered:  January, 1990
 Symptoms:    .COM growth, 8th day any month corrupts BOOT, FAT,
              & Partition tables.
 Origin:      Taiwan
 Eff Length:  743 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V56+, F-Prot, Pro-Scan 1.4+, VirexPC, NAV,
              IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, NAV, or delete infected files
 General Comments:
       The Taiwan virus was first isolated in January, 1990 in
       Taiwan, R.O.C.  This virus infects .COM files, including
       COMMAND.COM, and does not install itself into system memory.

       Each time a program infected with the Taiwan virus is executed, the
       virus will attempt to infect up to 3 .COM files.  The current
       default directory is not first infected, instead the virus will
       start its search for candidate files in the C: drive root directory.
       Once an uninfected .COM file is located, the virus infects the file
       by copying the viral code to the first 743 bytes of the file, the
       original first 743 bytes of the file is relocated to the end of the
       .COM file.  A bug exists in this virus, if the uninfected .COM file
       is less than 743 bytes in length, the resulting infected .COM file
       will always be 1,486 bytes in length.  This effect is due to the
       virus not checking to see if it read less than 743 bytes of the
       original file before infecting it.

       The Taiwan virus is destructive.  On the 8th day of any month, when
       an infected program is run the virus will perform an absolute disk
       write for 160 sectors starting at logical sector 0 on the C: and
       D: drives.  In effect, this logical write will result in the FATs
       and root directory being overwritten.

       Known variant(s) of Taiwan include:
       Taiwan-B : Apparently an earlier version of the Taiwan virus, this
                  variant will hang the system when infected files are
                  executed, but after it has infected another file using
                  the selection mechanism indicated for the Taiwan virus.


 Virus Name:  Taiwan 3
 Aliases:
 V Status:    Rare
 Discovered:  June, 1990
 Symptoms:    .COM & .EXE growth, decrease in available free memory,
              system hangs
 Origin:      Taiwan
 Eff Length:  2,900 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V64+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Clean-Up V71+, Scan/D, or delete infected files
 General Comments:
       The Taiwan 3 Virus was isolated in June, 1990 in Taiwan, R.O.C.  It
       was dubbed the Taiwan 3 Virus by John McAfee because it is the third
       virus from Taiwan, the other two are Taiwan and Disk Killer.  This
       virus is not related to either of these two viruses.

       The first time a program infected with the Taiwan 3 Virus is executed
       on a system, the virus will install itself memory resident in low
       system free memory.  Available free memory will decrease by 3,152
       bytes.  The virus hooks interrupt 21.

       After becoming memory resident, Taiwan 3 will infect any program
       which is executed.  .COM files will increase in length by 2,900
       bytes, .EXE files will increase by between 2,900 and 2,908 bytes.
       Overlay files may also become infected as well.

       It is unknown what the activation criteria is for this virus, or
       what it does besides spreading.

       Also see: Fu Manchu


 Virus Name:  Taiwan 4
 Aliases:     2576
 V Status:    Common
 Discovered:  October, 1990
 Symptoms:    TSR; .COM & .EXE file growth; system slowdown
 Isolated:    USA and Thailand
 Origin:      Taiwan
 Eff Length:  2,576 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions:  Clean-Up V71+, Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The Taiwan 4, or 2576, Virus was isolated in October, 1990.  While one
       copy of this virus was submitted by a user of Excalibur! who indicated
       that it had been received from a download of AutoCad from another BBS,
       a second copy was submitted to John McAfee from Thailand on
       approximately the same date.  This virus appears to have originated in
       Taiwan, and is based on the Taiwan 3 virus.  It is a memory resident
       infector of .COM and .EXE files, but will not infect COMMAND.COM.

       When a program infected with the Taiwan 4 Virus is executed, the virus
       will check to see if it is already memory resident.  If the virus isn't
       already in memory, the virus will install itself memory resident as a
       low system memory TSR of 2,832 bytes.  Interrupts 08 and 21 will be
       hooked by the virus.

       After the virus is resident, the virus will start to slow down the
       system gradually.  After approximately 30 minutes, it will have slowed
       the system down by approximately 30 percent.

       Any .COM or .EXE file executed with Taiwan 4 active in memory will
       become infected.  Infected programs will have their file length
       increased by 2,576 bytes for .COM files, and 2,576 - 2,590 bytes for
       .EXE files.  The virus is located at the beginning of .COM files, and
       the end of .EXE files.  The following text message can be found in all
       infected programs:

               "To Whom see this: Shit! As you can see this document,
                you may know what this program is. But I must tell you:
                DO NOT TRY to WRITE ANY ANTI-PROGRAM to THIS VIRUS.
                This is a test-program, the real dangerous code will
                implement on November. I use MASM to generate varius
                virus easily and you must use DEBUG against my virus
                hardly, this is foolish. Save your time until next month.
                OK? Your Sincerely, ABT Group., Oct 13th, 1989 at FCU."

       Another text string that can be found in all infected programs is:
       "ACAD.EXECOMMAND.COM".


 Virus Name:  Tequila
 Aliases:     Stealth
 V Status:    New
 Discovered:  April, 1991
 Symptoms:    .EXE growth; Partition Table Modified; File Allocation Errors;
              Decrease in total system and available memory
 Origin:      Switzerland
 Eff Length:  2,468 Bytes
 Type Code:   PRtEX - Parasitic Resident .EXE & Partition Table Infector
 Detection Method:
 Removal Instructions:  Delete infected files & Replace Partition Table
 General Comments:
       The Tequila Virus was isolated in April, 1991.  It is originally from
       Switzerland, and at the time of its isolation was thought to be common
       in Europe.  Tequila is a memory resident partition table and .EXE file
       infector which uses a complex encryption method and garbling to avoid
       disassembly and detection by using a scan or search string.

       The first time a program infected with Tequila is executed on a system,
       the virus will check to see if it has already infected the hard disk
       partition table.  If the partition table has not been previously
       infected, Tequila will write an unencrypted copy of itself to the last
       six sectors of the system hard disk, as well as modify the hard disk
       partition table so that it will be infectious.  Tequila will not
       install itself memory resident at this time, and it will not infect
       programs.

       Later, when the system is rebooted from the system hard disk, Tequila
       will become memory resident.  It will be located at the top of system
       memory but below the 640K DOS boundary.  Interrupt 12's return will be
       moved, preventing the virus from being overwritten in memory.
       Interrupts 13 and 21 will be hooked by the virus.  Total system memory
       and available free memory, as indicated by the DOS ChkDsk program, will
       be 3,072 bytes less than expected.

       After Tequila is memory resident, it will .EXE programs when they are
       executed.  Infected .EXE programs will increase in size by 2,468 bytes,
       but this increase will not be able to be seen in the DOS disk directory
       if the virus is memory resident.  The virus will be located at the end
       of infected programs.  The infected program's date and time in the
       disk directory will not be altered.

       The following text will be able to be found on the last few sectors
       of the hard disk on infected systems.  This text is encrypted in
       infected programs:

               "Welcome to T.TEQUILA's latest production.
                Contact T.TEQUILA/P.o.Box 543/6312 St'hausen
                Switzerland.
                Loving thought to L.I.N.D.A.
                BEER and TEQUILA forever !"
               "$Execute: mov ax, FE03 / int 21. Key to go on!"

       Systems infected with Tequila will notice file allocation errors
       being detected with the DOS ChkDsk command when the virus is memory
       resident.  If ChkDsk is executed with the /F option, program corruption
       may result.

       Anti-viral programs which perform CRC checking may not be able to
       detect Tequila on files, regardless of whether the virus is memory
       resident.

       It is unknown if Tequila carries an activation mechanism, or what it
       may do upon activation.


 Virus Name:  Tester
 Aliases:     TestVir
 V Status:    Rare
 Discovered:  April, 1991
 Symptoms:    .COM growth; Messages
 Origin:      United States
 Eff Length:  1,000 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method: ViruScan V76+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Tester, or TestVir, Virus was received in April, 1991.  Its origin
       is unknown.  This virus is a non-resident infector of .COM files.  It
       will infect COMMAND.COM.

       When a program infected with Tester is executed, the virus will display
       the following messages, requiring a response by the system user:

               "This is TESTVIRUS B V1.4 !

                1 = infect COM-files of this directory + run orig. prog.
                5 = run only orig. program
                9 = abort"

       If a "1" is entered by the system user, the virus will then infect all
       of the .COM programs in the current directory, and then execute the
       original program.  When Tester infects .COM programs, it will display
       one of the following two lines, indicating which .COM program it is
       currently processing.  The first line is displayed for the program if
       it was previously infected, the second line only if it is currently
       infecting the program:

               "Already infected:  xxxxxxxx.COM"
               "INFECTED: ------>  xxxxxxxx.COM"

       Entering a "5" will result in no additional programs being infected, and
       the original program is executed.  Finally, entering a "9" will result
       in the program terminating and the user being returned to a DOS prompt.

       Programs infected with Tester will increase in size by 1,000 bytes, the
       virus will be located at the beginning of the infected file.  The
       program's date and time in the DOS disk directory will have also been
       updated to the date and time when infection occurred.


 Virus Name:  The Plague
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    "Program too big to fit in memory" message;
              Programs do not execute properly; Long disk accesses;
              Message and disk overwrite
 Origin:      United States
 Eff Length:  590 Bytes
 Type Code:   ONAK - Overwriting Non-Resident .COM & .EXE Infector
 Detection Method:
 Removal Instructions:  Delete infected files
 General Comments:
       The Plague Virus was isolated in January, 1991 in the United States.
       This virus is a non-memory resident infector of .COM and .EXE files,
       including COMMAND.COM.

       When a program infected with The Plague is executed, the virus will
       attempt to infect up to three programs on the current drive, starting
       in the current directory.  Infected programs can be either .COM or
       .EXE files, and COMMAND.COM can become infected.  This virus is an
       overwriting virus.  It replaces the first 590 bytes of the program
       being infected with a copy of itself.  The file date and time in the
       disk directory are not altered.

       Programs infected with The Plague will not function properly.  For .EXE
       files, the following message will usually be displayed upon program
       execution:

               "Program too big to fit in memory"

       This message may also occur for some .COM programs, but not usually.

       The Plague activates when an infected program is executed and it can
       not find an uninfected program to infect, though there is some
       randomness to whether or not the activation will actually occur.
       When this virus activates, the following message is displayed:

               "Autopsy indicates the cause of
                death was THE PLAGUE
                Dedicated to the dudes at SHHS
                VIVE LE SHE-MAN!"

       While the message is being displayed, the disk in the current drive
       will be overwritten with garbage characters, rendering it unrecoverable.

       Programs infected with The Plague cannot be disinfected since the
       first 590 bytes of the program no longer exists.  The programs must
       be deleted and replaced with clean copies.


 Virus Name:  Tiny Family
 Aliases:     Tiny-133, Tiny-134, Tiny-138, Tiny-143, Tiny-154, Tiny-156,
              Tiny-158, Tiny-159, Tiny-160, Tiny-167, Tiny-198
 V Status:    Rare
 Discovery:   July, 1990
 Symptoms:    .COM file growth
 Origin:      Bulgaria
 Eff Length:  133 - 198 Bytes (see below)
 Type Code:   PRC - Parasitic Resident .COM Infector
 Detection Method: ViruScan V66+, Pro-Scan 2.01+ (larger variants only),
              IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Tiny Family of Viruses was received by the author in July 1990
       from Vesselin Bontchev of Bulgaria.  All the viruses in this grouping
       share the same characteristics, with the only real difference is the
       effective length of the viral code.  There were five (5) viruses
       included in the "family" as of July, 1990: Tiny-158, Tiny-159,
       Tiny-160, Tiny-167, and Tiny-198.  In October 1990, five (5)
       additional viruses in this family were received from Vesselin
       Bontchev: Tiny-134, Tiny-138, Tiny-143, Tiny-154, and Tiny-156.
       In December 1990, an eleventh member was added to this family:
       Tiny-133.

       The first time a file infected with one of the Tiny Family viruses
       is executed on a system, the virus will install itself memory resident
       at memory segment 60h.  This area of memory is normally only used by
       DOS when the system is booted, after that it is never used or
       referenced.  Interrupt 21 will be hooked by the virus.

       After the virus is memory resident, the virus will infect any .COM
       program that is executed.  Infected programs will have a file length
       increase of between 134 - 198 bytes, depending on which variant is
       present on the system.  The file's date and time in the directory will
       also have been updated to the system date and time when the infection
       occurred.

       The Tiny Family of Viruses currently does not do anything but
       replicate.

       The viruses in this "family" are not related to the Tiny Virus
       documented below.

       Known members of the Tiny Family are:
       Tiny-133 : Similar to Tiny-134, this variant's effective length is
                  133 bytes.  The bugs in Tiny-134 have been fixed, this
                  virus is an excellent replicator.  This variant has also
                  been altered so that it cannot be detected by anti-viral
                  utilities which were aware of other members of this family.
       Tiny-134 : This variant's effective length is 134 bytes.  This
                  variant is the only member of this family which is not
                  a very viable virus, it will usually hang the system
                  when it attempts to infect .COM files.
       Tiny-138 : Same as above, effective length is 138 bytes.
       Tiny-143 : Same as above, effective length is 143 bytes.
       Tiny-154 : Same as above, effective length is 154 bytes.
       Tiny-156 : Same as above, effective length is 156 bytes.
       Tiny-158 : Same as above, effective length is 158 bytes.
       Tiny-159 : Same as above, effective length is 159 bytes.
       Tiny-160 : Same as above, effective length is 160 bytes.
       Tiny-167 : Same as above, effective length is 167 bytes.
       Tiny-198 : Same as above, effective length is 198 bytes.

       Also see: Tiny Virus


 Virus Name:  Tiny Virus
 Aliases:     163 COM Virus, Tiny 163 Virus, Kennedy-163
 V Status:    Rare
 Discovery:   June, 1990
 Symptoms:    COMMAND.COM & .COM file growth
 Origin:      Denmark
 Eff Length:  163 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V64+, VirexPC, F-Prot 1.12+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, F-Prot 1.12+, or Delete infected files
 General Comments:
       The 163 COM Virus, or Tiny Virus, was isolated by Fridrik Skulason
       of Iceland in June 1990.  This virus is a non-resident generic
       .COM file infector, and it will infect COMMAND.COM.

       The first time a file infected with the 163 COM Virus is executed,
       the virus will attempt to infect the first .COM file in the
       current directory.  On bootable diskettes, this file will normally
       be COMMAND.COM.  After the first .COM file is infected, each time
       an infected program is executed another .COM file will attempt to
       be infected.  Files are infected only if their original length is
       greater than approximately 1K bytes.

       Infected .COM files will increase in length by 163 bytes, and have
       date/time stamps in the directory changed to the date/time the
       infection occurred.  Infected files will also always end with this
       hex string: '2A2E434F4D00'.

       This virus currently does nothing but replicate, and is the
       smallest MS-DOS virus known as of its isolation date.

       The Tiny Virus may or may not be related to the Tiny Family documented
       elsewhere in this listing.

       Also see: Tiny Family


 Virus Name:  Traceback
 Aliases:     3066
 V Status:    Extinct
 Discovered:  October, 1988
 Symptoms:    .COM & .EXE growth, TSR, graphic display 1 hour after boot
 Origin:
 Eff Length:  3,066 bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  M-3066, VirClean, F-Prot, VirexPC, Pro-Scan 1.4+,
              VirHunt 2.0+, NAV, CleanUp V77+, or delete infected files
 General Comments:
       The Traceback virus infects both .COM and .EXE files, adding
       3,066 bytes to the length of the file.  After an infected
       program is executed, it will install itself memory resident
       and infect other programs that are opened.  Additionally, if
       the system date is after December 5, 1988, it will attempt to
       infect one additional .COM or .EXE file in the current
       directory.  If an uninfected file doesn't exist in the current
       directory, it will search the entire disk, starting at the
       root directory, looking for a candidate.  This search
       process terminates if it encounters an infected file before
       finding a candidate non-infected file.

       This virus derives its name from two characteristics.  First,
       infected files contain the directory path of the file causing
       the infection within the viral code, thus is it possible
       to "trace back" the infection through a number of files.  Second,
       when it succeeds in infected another file, the virus will
       attempt to access the on-disk copy of the program that the
       copy of the virus in memory was loaded from so that it can
       update a counter in the virus.  The virus takes over disk
       error handling while trying to update the original infected
       program, so if it can't infect it, the user will be unaware
       that an error occurred.

       The primary symptom of the Traceback virus having infected
       the system is that if the system date is after December 28,
       1988, the memory resident virus will produce a screen display
       with a cascading effect similar to the Cascade/1701/1704
       virus.  The cascading display occurs one hour after system
       memory is infected.  If a keystroke is entered from the key-
       board during this display, a system lockup will occur.  After
       one minute, the display will restore itself, with the characters
       returning to their original positions.  This cascade and
       restore display are repeated by the virus at one hour
       intervals.

       Known variant(s) of the Traceback virus are:
       Traceback-B : Similar to the Traceback virus, the major differences
                     are that Traceback-B will infect COMMAND.COM and there
                     is no cascading display effect after the virus has
                     been resident for one (1) hour.  Infected files will
                     also not contain the name of the file from which the
                     virus originally became memory resident, but instead
                     the name of the current file.  A text string:
                     "MICRODIC MSG" can be found in files infected with
                     Traceback-B.  If the system is booted from a diskette
                     whose copy of COMMAND.COM is infected, attempting to
                     execute any program will result in a memory allocation
                     error and the system being halted.
                     Origin: Spain, March 1990.
       Traceback-B2: Similar to Traceback-B2, this variant has the cascading
                     display effect after the virus has been resident in
                     memory for one (1) hour.  The text string " XPO DAD     "
                     replaces the "MICRODIS MSG" text string in Traceback-B.
                     Origin: Spain, May 1990.

       Also see: Traceback II


 Virus Name:  Traceback II
 Aliases:     2930
 V Status:    Extinct
 Discovered:  October, 1988
 Symptoms:    .COM & .EXE growth, TSR, graphic display 1 hour after boot
 Origin:
 Eff Length:  2,930 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: Scan/D/X, F-Prot, VirexPC, Pro-Scan 1.4+, VirHunt 2.0+,
              NAV, or delete infected files.
 General Comments:
       The Traceback II virus is a variant of the Traceback (3066)
       virus.  It is believed that Traceback II predates the
       Traceback virus, however the Traceback virus was isolated
       and reported first.  As with the Traceback virus, the
       Traceback II virus is memory resident and infects both .COM
       & .EXE files.

       The comments indicated for the Traceback virus generally
       apply to the Traceback II virus, with the exception that the
       file length increase is 2,930 bytes instead of 3,066 bytes.

       Known variant(s) of the Traceback II Virus are:
       Traceback II-B: Similar to Traceback II, this variant will infect
                       COMMAND.COM.  When the cascading effect occurs, the
                       screen will not be restored, instead the system will
                       be hung requiring it to be powered off and rebooted.

       Also see: Traceback


 Virus Name:  Turbo 448
 Aliases:     @ Virus, Turbo @, Polish-2
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    .COM growth; File not found errors with some utilities.
 Origin:      Hungary
 Eff Length:  448 Bytes
 Type Code:   PRCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V71+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Turbo 448, or @ Virus, was discovered in Hungary in November, 1990.
       This virus is a memory resident infector of .COM files, including
       COMMAND.COM.

       The first time a program infected with the Turbo 448 Virus is executed,
       the virus will install itself memory resident at the end of the
       Command Interpretor in memory.  Total system memory and available free
       memory will not decrease.  Interrupt 21 will be hooked by the virus.

       The Turbo 448 Virus is unusual in that it does not infect programs when
       they are executed.  Instead, it infects .COM files when they are openned
       for some other reason besides execution.  For example, if the virus is
       memory resident a program A.COM is copied to B.COM, both programs will
       become infected by the virus.

       Infected files will increase in length by 448 bytes, with the virus
       being located at the end of the file.  The program's date and time in
       the disk directory will also have been updated to the system date and
       time when the file was infected.  The following text string can be
       found at the end of all infected programs:

               "Udv minden nagytudasunak! Turbo @"

       Another interesting behavior of this virus is that when the virus is
       memory resident, anti-viral products which are unaware of the Turbo 448's
       presence in memory will not function properly.  After the third file is
       read, the program may fail due to a "file not found" error being received
       when it attempts to open the fourth program.

       Also see: Turbo Kukac 9.9


 Virus Name:  Turbo Kukac
 Aliases:     Kukac, Turbo Kukac 9.9, Polish-2
 V Status:    Rare
 Discovered:  November, 1990
 Symptoms:    .COM growth; Decrease in total system and free available memory;
              File not found errors with some utilities.
 Origin:      Hungary
 Eff Length:  512 Bytes
 Type Code:   PRCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V71+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Turbo Kukac, or Kukac, Virus was discovered in Hungary in November,
       1990.  This virus is a memory resident infector of .COM files, including
       COMMAND.COM.  It is very similar to the Turbo 448 Virus.

       The first time a program infected with the Turbo Kukac Virus is executed,
       the virus will install itself memory resident following the Command
       Interpretor and any previously loaded TSRs.  Total system memory and
       available free memory will decrease by 1,040 bytes.  Interrupts 05 and
       21 will be hooked by the virus.  Note that this virus does not use a low
       system memory TSR, but instead creates a sort of "hole" in memory for
       its usage.

       Like the Turbo 448 Virus, this virus does not infect program when
       they are executed.  Instead, it infects .COM files when they are openned
       for some other reason besides execution.  For example, if the virus is
       memory resident a program A.COM is copied to B.COM, both programs will
       become infected by the virus.

       Infected files will increase in length by 512 bytes with the virus being
       located at the end of the file.  The program's date and time in the
       directory will also have been updated to the system date and time when
       the file was infected.  The following text string can be found at the
       end of all infected programs:

               "Turbo Kukac 9.9      $"

       An interesting behavior of this virus is that when the virus is
       memory resident, anti-viral products which are unaware of the Turbo
       Kukac's presence in memory will not function properly.  After the
       fourth file is read, the program may fail due to a "file not found"
       error being received when it attempts to open the fifth program.

       Also see: Turbo 448


 Virus Name:  Typo Boot
 Aliases:     Mistake
 V Status:    Rare
 Discovered:  June, 1989
 Symptoms:    BSC, Resident TOM, garbled printout.
 Origin:      Israel
 Eff Length:  N/A
 Type Code:   BRt - Resident Boot Sector Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  MDisk, Pro-Scan 1.4+, F-Prot, NAV, CleanUp V77+,
              or DOS SYS Command
 General Comments:
       The Typo Boot virus was first isolated in Israel by Y. Radai
       in June, 1989.  This virus is a memory resident boot sector
       infector, taking up 2K at the upper end of system memory once
       it has installed itself memory resident.

       The major symptom that will be noticed on systems infected
       with the Typo Boot virus is that certain characters in
       printouts are always replaced with other phonetically
       similar characters.  Since the virus also substitutes hebrew
       letters for other hebrew letters, the virus was most likely
       written by someone in Israel.  Digits in numbers may also
       be transposed or replaced with other numbers.  The substitutions
       impact printouts only, the screen display and data in files are
       not affected.

       The Typo Boot virus is similar structurally to the Ping Pong
       virus, and may be a variant of Ping Pong.  It can be removed
       from a disk by using MDisk, CleanUp, DOS SYS command, or
       just about any Ping Pong disinfector.


 Virus Name:  Typo COM
 Aliases:     Fumble, 867
 V Status:    Extinct
 Discovered:  November, 1989
 Symptoms:    .COM growth, Resident TOM, garbled printout (see text).
 Origin:      England
 Eff Length:  867 Bytes
 Type Code:   PRtC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  Scan/D/X, F-Prot, Pro-Scan 1.4+, VirHunt 2.0+,
              or delete infected files
 General Comments:
       The Typo COM virus is similar to the Typo Boot virus in that
       it will garble data that is sent to the parallel port once it
       has activated.  Unlike the Boot virus, the COM virus infects
       generic .COM files.  This virus was first reported by Joe
       Hirst of Brighton, UK, in November, 1989.

       The Typo COM virus only infects .COM files on even-numbered
       days.


 Virus Name:  USSR
 Aliases:
 V Status:    Rare
 Discovered:  October, 1990
 Symptoms:    .EXE growth; hard disk boot sector and partition table damage;
              system hangs; long program load times
 Origin:      USSR
 Eff Length:  576 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+
 Removal Instructions: Scan/D, or Delete infected Files
 General Comments:
       The USSR Virus was discovered in October, 1990 in the USSR.  It is
       an encrypted, non-resident generic infector of .EXE files.

       Each time a program infected with the USSR Virus is executed, it will
       search the currect directory for the first uninfected .EXE file.  If
       it finds one, it will attempt to infect it.  Sometimes when the virus
       attempts to infect a file, it will hang the system leaving the drive
       light on, however most of the time the virus is successful.  Infected
       files will increase in length by 576 to 586 bytes, with the virus
       located at the end of the file.

       Systems infected with this virus may go to boot their system from its
       hard disk only to find that the hard disk's boot sector has been
       removed, and the partition table has been damaged, thus rendering the
       hard disk inaccessible.  This damage can be repaired using Norton
       Disk Doctor, or MDisk with the /P option.

       Infected systems will also experience longer than normal load times
       when infected programs are executed.  The longer than normal load time
       is due to the virus searching for a file to infect, and then infecting
       the candidate file if one was found.


 Virus Name:  USSR 311
 Aliases:     V-311
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    .COM growth; COMMAND.COM renamed to COMMAND.CON
 Origin:      USSR
 Eff Length:  311 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 311, or V-311, Virus was submitted in January, 1991.  It
       originated in the USSR.  This virus is a non-resident infector of .COM
       programs, including COMMAND.COM.

       When a program infected with USSR 311 is executed, the virus will check
       the system time to see if the seconds value is equal to one of 16
       values.  If it was equal to one of those 16 values, COMMAND.COM will be
       renamed to COMMAND.CON.  Whether or not the rename of COMMAND.COM
       occurred, the virus will then infect one .COM program in the current
       directory.

       Infected .COM programs will increase in length by 311 bytes, the virus
       will be located at the end of the infected file.  The file's time in
       the disk directory will also be modified to be 11:19:32, the infection
       marker for this virus.  The file date in the directory is not altered.

       USSR 3111 will also alter the file attributes for the file in the
       directory.  In particular, bits 8 thru 15 will be reset, which may
       produce unexpected results in environments that make use of these
       bits.


 Virus Name:  USSR 492
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth; File date/time changes
 Origin:      USSR
 Eff Length:  495 - 508 Bytes
 Type Code:   PRfCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 492 Virus was submitted in December, 1990 and is from the
       USSR.  This virus is a memory resident .COM file infector, it will
       infect COMMAND.COM.

       When the first program infected with USSR 492 is executed, the virus
       will install itself memory resident in high system memory, but below
       the 640K DOS boundary.  This memory is not reserved by the virus.
       Interrupt 21 will be hooked by the virus.  At the time of going memory
       resident, the virus will check to determine if COMMAND.COM on the C:
       drive is infected, if it isn't, then the virus will infect it.

       Once USSR 492 is memory resident, it will infect any .COM program which
       is executed.  Execution of COMMAND.COM on the A: drive is the only way
       to infect COMMAND.COM on A:.

       Programs infected with USSR 492 will have a file length increase of
       495 to 508 bytes.  The virus will be located at the end of infected
       programs.  Infected programs will also have their date and time in the
       disk directory changed to the system date and time when infection
       occurred.

       USSR 492 does not appear to do anything besides replicate.


 Virus Name:  USSR 516
 Aliases:     Leapfrog
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth
 Origin:      USSR
 Eff Length:  516 Bytes
 Type Code:   PRCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 516 Virus was submitted in December, 1990.  It is from the
       USSR.  This virus is a memory resident infector of .COM programs,
       including COMMAND.COM.  It infects on file execution.

       The first time a program infected with the USSR 516 Virus is executed,
       the virus will install itself memory resident in a "hole in memory"
       between MSDOS and the DOS Stacks.  This area will be labelled
       DOS Data.  Interrupt 21 will be hooked by the virus.  There will be
       no change in total system memory or available free memory.

       After the virus is memory resident, it will infect .COM programs which
       are executed that had an uninfected file length which was greater than
       512 bytes.  Infected .COM programs will have their length increased
       by 516 bytes, the virus will be located at the end of the program.

       USSR 516 does not appear to do anything besides replicate.  The original
       submitted sample was not a natural infection of this virus, so this may
       be a research virus.


 Virus Name:  USSR 600
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth
 Origin:      USSR
 Eff Length:  600 Bytes
 Type Code:   PRhCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 600 Virus was submitted in December, 1990, and is from the
       USSR.  This virus is a memory resident infector of .COM programs,
       including COMMAND.COM.

       When the first program infected with USSR 600 is executed, the virus
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  The DOS ChkDsk program will indicate
       that total system memory and available free memory are 2,048 bytes
       less than expected.  This virus does not move the interrupt 12
       return.  USSR 600 uses interrupts 21 and 24.

       Once USSR 600 is memory resident, it will infect .COM programs which
       are executed if they have an original file length of at least 600
       bytes.  Infected files will increase in size by 600 bytes, and the
       virus's code will be located at the beginning of the infected program.

       It is unknown if this virus does anything besides replicate.


 Virus Name:  USSR 707
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth; decrease in total system and available memory
 Origin:      USSR
 Eff Length:  707 Bytes
 Type Code:   PRtCK - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 707 Virus was submitted in December, 1990.  It is from the
       USSR.  This virus is a memory resident infector of .COM programs,
       including COMMAND.COM.

       When the first program infected with the USSR 707 Virus is executed,
       this virus will install itself memory resident at the top of system
       memory but below the 640K DOS boundary.  It will move the interrupt 12
       return so that the virus in memory cannot be overwritten.  USSR 707
       makes use of interrupt 21, which will now map to the virus in high
       system memory.  Total system memory and available free memory will
       be 720 bytes less than expected.

       After USSR 707 is memory resident, any .COM program executed will
       become infected by the virus.  Infected .COM programs will have a
       file length increase of 707 bytes, the virus will be located at the
       end of the file.  If COMMAND.COM is executed, it will be infected.

       It is unknown if USSR 707 does anything besides replicate.


 Virus Name:  USSR 711
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM file growth; system hangs;
              decrease in total system and available memory
 Origin:      USSR
 Eff Length:  711 Bytes
 Type Code:   PRhC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 711 Virus was submitted in December, 1990, and comes from the
       USSR.  This virus is a memory resident infector of .COM files.  It does
       not infect COMMAND.COM.

       When the first program infected with USSR 711 is executed, the virus
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  This memory is reserved.  The virus also
       hooks interrupts 08, 13, and 21.  The DOS ChkDsk program will indicate
       that total system memory and available free memory is 704 bytes less
       than what the user expects.  The interrupt 12 return is not altered
       by this virus.

       After USSR 711 is memory resident, any .COM file which is executed that
       had an original file length of at least 1600 bytes will be infected by
       the virus.  Infected .COM files will increase in size by 705 to 717
       bytes, and the virus will be located at the end of the infected file.

       Systems infected with USSR 711 may notice occasional system hangs which
       may occur when this virus attempts to infect .COM programs.

       It is unknown if USSR 711 does anything besides replicate and
       occasionally hang the system when infecting files.


 Virus Name:  USSR 948
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM & .EXE growth; decrease in total system and available memory
 Origin:      USSR
 Eff Length:  948 Bytes
 Type Code:   PRhA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 948 Virus was received in December, 1990, and originated in
       the USSR.  This virus is a memory resident infector of .COM and .EXE
       files, and will also infect COMMAND.COM.

       When the first program infected with USSR 948 is executed, this virus
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  The interrupt 12 return will not be
       altered, although the memory in use by the virus is reserved.
       Interrupts 1C and 21 will be hooked by the virus.

       After USSR 948 is memory resident, and .COM or .EXE program which is
       executed or openned for any reason will become infected by the virus.
       Infected programs, with the exception of COMMAND.COM, will increase
       in size by between 950 to 963 bytes.  In the case of COMMAND.COM, the
       virus will overwrite a portion of the stack space located in the file,
       so the file will not have a length change.  In all cases, the file
       date and times in the disk directory are not altered.  Infected
       programs will have the virus located at the end of the file.

       It is unknown if USSR 948 does anything besides replicate.


 Virus Name:  USSR 1049
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM & .EXE growth; system hangs;
              decrease in total system and available free memory
 Origin:      USSR
 Eff Length:  1,049 Bytes
 Type Code:   PRhA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 1049 virus was received in December, 1990.  It originated in
       the USSR.  This virus is a memory resident infector of .COM and .EXE
       files, and does not infect COMMAND.COM.

       When the first program infected with USSR 1049 is executed, the virus
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  This memory will be 1,056 bytes in
       size and is reserved.  The interrupt 12 return is not moved. Interrupt
       21 will be hooked by the virus.

       After USSR 1049 is memory resident, the virus will infect .COM and
       .EXE files when they are executed.  The virus, however, will not infect
       very small .EXE files.  Infected files will increase in size by
       1,051 to 1,064 bytes, the virus will be located at the end of the
       infected program.

       Systems infected with the USSR 1049 Virus may experience system hangs
       when attempting to execute .EXE programs.  These hangs occassionally
       occur when the virus infects .EXE program, though the program being
       infected will actually be infected.

       It is unknown if USSR 1049 does anything besides replicate.


 Virus Name:  USSR 1689
 Aliases:     SVC V4.00
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM & .EXE growth; system hangs
 Origin:      USSR
 Eff Length:  1,689 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 1689 Virus was received in December, 1990.  It is from the
       USSR.  This virus is not a very viable virus, though it does infect
       both .COM and .EXE programs.

       When the first program infected with USSR 1689 is executed, this virus
       will install itself memory resident in the in-memory command
       interpretor.

       After the virus is memory resident, the virus will infect the next
       .COM or .EXE program executed, though a system hang will also occur.
       Infected programs will increase in size by 1,689 bytes, though on files
       larger than 1,689 bytes, the virus will hide the file length increase
       if the virus is already in memory.  Files originally smaller than 1,689
       bytes will indicate a file size increase in the DOS directory when the
       virus is resident.  In all cases, the virus will be located at the end
       of infected programs.

       With the system hang which occurs each time a program is infected by
       this virus, it is not a very viable virus, and should not be considered
       a threat in its current state.


 Virus Name:  USSR 2144
 Aliases:
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM & .EXE growth; decrease in total system and available memory
 Origin:      USSR
 Eff Length:  2,144 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The USSR 2144 Virus was submitted in December, 1990, and is from the
       USSR.  This virus is a memory resident infector of .COM and .EXE files,
       including COMMAND.COM.

       When the first program infected with the USSR 2144 Virus is executed,
       the virus will install itself memory resident at the top of system
       memory but below the 640K DOS boundary.  The DOS ChkDsk program will
       indicate memory values that show 4,608 bytes less total system memory
       and available free memory than expected.  This virus does not move
       the interrupt 12 return.  The virus also directly alters the interrupt
       page in memory so that some interrupts will now execute the virus's
       code.

       After USSR 2144 is memory resident, and program which was originally
       greater in length than 2K that is executed or openned for reason will
       become infected by the virus. Infected .COM programs will increase in
       length by 2,144 bytes.  .EXE programs will increase in length by 2,144
       to 2,59 bytes.  In both cases, the virus will be located at the end
       of infected files.  Infected files will not have their date and time in
       the disk directory altered, and this virus does not hide the change in
       file length of infected files.

       It is unknown if USSR 2144 does anything besides replicate.


 Virus Name:  V651
 Aliases:     Eddie 3, Stealth Virus
 V Status:    Rare
 Discovered:  April, 1990
 Symptoms:    .COM & .EXE growth, decrease in system and free memory,
              file allocation errors
 Origin:      Sofia, Bulgaria
 Eff Length:  651 Bytes
 Type Code:   PRtA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V66+, VirHunt 2.0+, IBM Scan 2.00+
 Removal Instructions: CleanUp V77+, VirHunt 2.0+, or Delete infected files
 General Comments:
       The V651, or Eddie 3, Virus was isolated in Sofia, Bulgaria in
       April 1990 by Vesselin Bontchev.  V651 is believed to have been
       written by the same author as Dark Avenger, V1024, and V2000.
       This virus is a generic infector for .COM and .EXE files.

       The first time a program infected with V651 is executed, the virus
       will install itself memory resident.  Using the DOS CHKDSK program,
       total system memory, as well as available free memory, will be
       decreased by 688 bytes.

       Later, as programs with a length of 651 bytes or greater are executed,
       they will be infected by the virus.  Infected files increase in length
       by 651 bytes, though the increase in file length will not be seen by
       performing a directory command with the virus present in memory. The
       total available disk space will also be adjusted by the virus so that
       the decrease in available disk space due to the virus's activities
       cannot be seen.  Powering off the system and booting from a known
       clean boot diskette, followed by issuing a directory command will
       result in the correct infected file lengths being displayed as well
       as the actual available space on the disk.

       Infected files can be easily identified as the text string "Eddie
       Lives." appears near the end of the infected file.  These files will
       also be 651 bytes longer than expected when the virus is not
       present in memory.

       A side effect of the V651 virus is that lost clusters may occur on
       infected systems if the CHKDSK /F command is used.  While this does
       not occur for all infected files, the number of errors reported by
       CHKDSK will be much higher statistically when V651 is present.

       Unlike Dark Avenger and V2000, this virus does not infect
       files on any file open.  It only infects when programs are executed.

       Also see: Dark Avenger, V1024, V2000


 Virus Name:  V800
 Aliases:     Live after Death Virus, Stealth Virus
 V Status:    Rare
 Discovered:  May, 1990
 Symptoms:    .COM growth, decrease in total system and available memory
 Origin:      Bulgaria
 Eff Length:  800 Bytes
 Type Code:   PRC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan V63+, Pro-Scan 1.4+, F-Prot 1.12+, NAV
 Removal Instructions: CleanUp V64+, Scan/D, F-Prot 1.12+, or
              delete infected files
 General Comments:
       The V800, or Live after Death, Virus was isolated in Bulgaria by
       Vesselin Bontchev in May, 1990.  The V800 is a self-encrypting
       memory resident .COM infector, and it does not infect COMMAND.COM.
       This virus is thought to have been written by the same person as
       the Dark Avenger virus since many of the same techniques are
       used.

       The virus has received an alias of the Live after Death Virus as
       the virus contains the "Live after Death" string, though it
       cannot be seen in infected files as the virus is encrypted.

       The first time an infected program is run on a system, the V800
       Virus will install itself memory resident.  In the process of
       installing itself resident, it will decrease available system
       memory by 16K, using 8,192 Bytes for itself in the top of
       available free memory.  It will also hook interrupt 2A.

       Once in memory, every time a .COM file is attempted to be
       executed, the virus will check to see if it is a candidate for
       infection.  Whether the file will be infected depends on the
       size of the .COM file when it is attempted to be executed.  In
       no event is a .COM file smaller than 1024 bytes infected, but
       not all .COM files over 1024 bytes are infected either.

       The V800 Virus will reinfect .COM files, with the file's size
       increasing by 800 bytes with each infection.  It does not,
       however, infect .COM files more than eight times.

       Known variant(s) of the V800 Virus include:
       V800M   : Very similar to V800, the major difference is that V800M
                 will infect files on both file open and file execute,
                 putting this variant into the "Stealth" virus category.
                 When the virus becomes memory resident, total system and free
                 memory will decrease by only 8,192 bytes.  This variant
                 does not have the "Live after Death" string in it.


 Virus Name:  V801
 Aliases:     V791
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM & .EXE growth; System hangs
 Origin:      USA
 Eff Length:  791 Bytes
 Type Code:   PNAK - Parasitic Non-Resident .COM & .EXE Infector
 Detection Method:  ViruScan V76+
 Removal Instructions: Scan/D/A, or Delete infected files
 General Comments:
       The V801 Virus was received in March, 1991 from the United States.
       This virus is a non-resident, direct action infector of .COM and .EXE
       programs.  It will infect COMMAND.COM.

       When a program infected with V801 is executed, the virus will search
       the current directory for an uninfected .EXE program.  If one is found,
       it will infect the program.  If an uninfected .EXE program is not found,
       the virus will then search for an uninfected .COM program in the
       current directory, and infect it.

       Programs infected with V801 will increase in size by 791 to 808 bytes.
       .COM programs will have the virus located at their beginning.  .EXE
       programs will have the virus located at the end of the infected file.
       The program's date and time in the disk directory will not be altered.

       Some infected programs may cause a system hang when they are attempted
       to be executed.

       V801 doesn't appear to do anything besides replicate.


 Virus Name:  V1024
 Aliases:     Dark Avenger III, Stealth Virus, Diamond
 V Status:    Rare
 Discovered:  May, 1990
 Symptoms:    TSR; decrease in available free memory
 Origin:      Bulgaria
 Eff Length:  1,024 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V64+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The V1024, or Dark Avenger III, Virus was discovered in Bulgaria in
       April 1990 by Daniel Kalchev.  V1024 is a memory resident generic
       infector of .COM and .EXE files.  It is believed to have been written
       by the same person that wrote Dark Avenger and V2000.  This virus may
       actually be an earlier version of the Dark Avenger virus, it has many
       of the same characteristics, though it does not infect all files when
       they are opened for any reason.

       The first time a program infected with V1024 is executed, the virus
       will install itself memory resident.  At this time, it checks to see
       if several interrupts are being monitored, including interrupts 1
       and 3.  If interrupts 1 and 3 are monitored, V1024 allow the current
       program to run, but any subsequent program executed will hang the
       system and V1024 will not replicate.  When V1024 is memory resident,
       infected systems will experience a decrease in free memory by 1,072
       bytes.  Total system memory will not have changed.  The virus will
       have remapped several interrupts by altering their location in the
       interrupt map page in memory.  These interrupts will now be controlled
       by V1024.

       After V1024 becomes memory resident, the virus will infect any
       program executed which is greater in length than 1,024 bytes.  Both
       .COM and .EXE files are infected, COMMAND.COM is not infected.
       Infected files increase in length by 1,024 bytes, though this increase
       will not appear if the virus is present in memory and a DIR listing
       is done.

       V1024 infected files can be identified by a text string which
       appears very close to the end of infected files.  The text string is:
       '7106286813'.

       V1024 does not appear contain any activation date.

       Known variant(s) of V1024 include:
       Diamond    : Similar to V1024, Diamond's main difference is that it
                    becomes memory resident at the top of system memory but
                    below the 640K DOS boundary.  Total system memory, and
                    available free memory, as measured by the DOS ChkDsk
                    program will decrease by 1,072 bytes.  Interrupts 08 and
                    21 will be hooked by the virus.
       Diamond-B  : Similar to Diamond, this variant has been slightly altered
                    to avoid detection by some anti-viral programs.

       Also see: Dark Avenger, V2000, V651


 Virus Name:  V2000
 Aliases:     Dark Avenger II, Stealth Virus, Travel Virus
 V Status:    Rare
 Discovered:  1989
 Symptoms:    TSR; .COM, .EXE, .OV? growth (see text); crashes;
              crosslinked files following CHKDSK.
 Origin:      Bulgaria
 Eff Length:  2,000 Bytes
 Type Code:   PRA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V59+, Pro-Scan 1.4+, AVTK 3.5+, VirHunt 2.0+,
              NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 1.4+, NAV, or delete infected files
 General Comments:
       The V2000, or Dark Avenger II, virus is a memory resident generic
       file infector.  The first isolated samples of this virus were
       received from Bulgaria, where it was isolated by Daniel Kalchev
       and Niki Spahiev.

       V2000 will infect .COM, .EXE, and Overlay files, as well as
       COMMAND.COM.  When the first infected file is executed, the virus
       installs itself memory resident, and then infected COMMAND.COM if
       it has not already been infected.  Then, when an executable file
       is opened for any reason, it is infected if it hasn't been
       previously infected.

       Increased file lengths will not be shown if the V2000 virus is
       present in memory when a DIR command is issued.  Issuing a
       CHKDSK /F command on infected systems may result in crosslinking
       of files since the directory information may not appear to match
       the entries in the file allocation table (FAT).

       Systems infected with the V2000 virus will experience unexpected
       system crashes, resulting in lost data.  Some systems may also
       become unbootable due to the modification of COMMAND.COM or the
       hidden system files.

       One of the following two text strings will appear in the viral code
       in infected files, thus accounting for the alias of Travel Virus used in
       Bulgaria:

              "Zopy me - I want to travel"
              "Copy me - I want to travel"

       There are reports from Bulgaria that the V2000 virus looks for and
       hangs the system if programs written by Vesselin Bontchev are
       attempted to be executed.  This would explain the presence of the
       following copyright notice within the viral code:

              "(c) 1989 by Vesselin Bontchev"

       Known variants of the V2000 virus include:
       V2000-B/Die Young : Similar to the V2000 virus, the main difference is
              that the text string "Zopy me - I want to travel" is now
              "Only the Good die young..." or "Mnly the Good die young..."
              and the encryption used by the virus is different.  This
              variant is actually the original virus, predating V2000.

       Also see: Dark Avenger, V1024, V651


 Virus Name:  V2100
 Aliases:     2100, Stealth Virus, UScan Virus
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    file allocation errors, decrease in system and free memory
 Origin:      Bulgaria
 Eff Length:  2,100 Bytes
 Type Code:   PRtA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V66+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D, NAV, or delete infected files
 General Comments:
       The V2100, or 2100, Virus was first isolated in Sofia, Bulgaria by
       Vesselin Bontchev in July 1990.  It is a resident generic infector
       of .COM, .EXE, and overlay files.  It will also infect COMMAND.COM.
       This virus appears to have been originally released into the public
       domain on an anti-viral program named UScan which was uploaded to
       a BBS in Europe.  While not all copies of UScan are carriers
       of this virus, there was one version which exists that has the virus
       embedded in its program code.  The virus cannot be detected on this
       trojan version using search algorithms for this virus.  V2100 is
       believed to have been written by the author of Dark Avenger.

       The first time a program infected with V2100 is executed, the virus
       will install itself memory resident above top of memory but below
       the 640K boundary.  The top of memory returned by interrupt 12 will
       be lower than expected by 4,288 bytes.  Likewise, free memory will
       have decreased by 4,288 bytes.  At this same point, V2100 will infect
       COMMAND.COM though the change in file length will be hidden by the
       virus.

       Once the virus is memory resident, it will infect any .COM, .EXE, or
       overlay file with a file length of at least 2100 bytes that is
       executed or opened for any reason.  The simple act of copying an
       executable file will result in both the source and target files
       becoming infected.  Infected files will be 2,100 bytes longer,
       though the virus will hide the change in file length so that
       it isn't noticeable when directories are listed.  In some cases,
       infected files will appear to be 2,100 bytes smaller than expected
       if the virus is present in memory.

       Systems infected with the V2100 virus will notice file allocation
       errors occurring, along with crosslinking of files.  Due to these
       errors, some files may become corrupted.  These file allocation
       errors are truly errors, they exist whether or not the virus is
       present in memory.

       A side note on the V2100 Virus: if the system had previously been
       infected with the Anthrax virus, V2100's introduction will result
       in the Anthrax virus again being present in the hard disk partition
       table.  This effect occurs because Anthrax stores a copy of itself
       on the last sectors of the hard disk.  When V2100 becomes resident,
       it searches the last 16 cylinders of the hard disk for a copy of
       Anthrax.  If V2100 finds the hidden copy of Anthrax, it copies it
       into the hard disk's partition table.  On the next system boot from
       the hard disk, Anthrax will once again be active on the system.


 Virus Name:  V2P2
 Aliases:
 V Status:    Research
 Discovered:  June, 1990
 Symptoms:    .COM file growth
 Origin:      Minnesota, USA
 Eff Length:  1,426 - 2,157 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D/X, or delete infected files
 General Comments:
       The V2P2 Virus is a research virus written by Mark Washburn and
       distributed to some anti-viral program authors in June of 1990.
       This virus, according to its author, has not been released.  This
       virus is a non-resident generic infector of .COM files.

       When a program infected with the V2P2 virus is executed, it will
       infect the first .COM file it finds in the current directory which
       is not infected with the virus.  The virus adds its code to the
       end of the file, and the infected file's length will increase
       between 1,426 and 2,157 bytes.

       Like the 1260 virus, this virus uses a complex encryption method.
       In fact, the encryption used with the 1260 virus is one of several
       possible encryptions that V2P2 may produce.  As a result, virus
       scanning software will often identify the 1260 virus in a file as
       being both 1260 and V2P2.  This identification is entirely valid
       as 1260 is a special case of V2P2.

       Also see: 1260, V2P6, V2P6Z


 Virus Name:  V2P6
 Aliases:
 V Status:    Research
 Discovered:  July, 1990
 Symptoms:    .COM file growth
 Origin:      Minnesota, USA
 Eff Length:  1,946 - 2,111 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan/X V67+, Pro-Scan 2.01+, NAV
 Removal Instructions: Scan/D/X, NAV, or delete infected files
 General Comments:
       The V2P6 Virus is a research virus written by Mark Washburn and
       distributed to some anti-viral program authors in July of 1990.
       This virus, according to its author, has not been released.  This
       virus is a non-resident generic infector of .COM files similar to
       the 1260, V2P2, and V2P6Z viruses.

       When a program infected with the V2P6 virus is executed, it will
       infect the first .COM file it finds in the current directory which
       is not infected with the virus.  The virus adds its code to the
       end of the file, and the infected file's length will increase
       between 1,946 and 2,111 bytes.

       Like the 1260 and other viruses by Mark Washburn, this virus uses
       a complex encryption method.  The encryption method used by V2P6 is
       more complex than that used in V2P2, but less complex than that used
       in the last known virus in this family, V2P6Z.  Like V2P2, an
       algorithmic approach must be used to identify this virus.

       Known variant(s) of V2P6 include:
       V2P6-B :  Similar to V2P6 in behavior, programs infected with this
                 variant will increase in size by 1,990 to 2,261 bytes.

       Also see: 1260, V2P2, V2P6Z


 Virus Name:  V2P6Z
 Aliases:
 V Status:    Research
 Discovered:  August, 1990
 Symptoms:    .COM file growth
 Origin:      Minnesota, USA
 Eff Length:  2,076 - 2,364 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method: NAV
 Removal Instructions: NAV, or Delete infected files
 General Comments:
       The V2P6Z Virus is a research virus written by Mark Washburn and
       distributed to some anti-viral program authors in August, 1990.
       This virus, according to its author, has not been released.  This
       virus is a non-resident generic infector of .COM files similar to
       the 1260, V2P2, and V2P6 viruses.

       When a program infected with the V2P6Z virus is executed, it will
       infect the first .COM file it finds in the current directory which
       is not infected with the virus.  The virus adds its code to the
       end of the file, and the infected file's length will increase
       between 2,076 and 2,364 bytes.

       Like the 1260 and other viruses by Mark Washburn, this virus uses
       a complex encryption method.  The encryption method used by V2P6Z is
       the most complex of the encryption methods employed by the viruses in
       this family of viruses.  Like V2P2 and V2P6, an algorithmic approach
       must be used to identify this virus as there is no possible
       identification string within the encrypted viral code.

       Also see: 1260, V2P2, V2P6


 Virus Name:  Vacsina
 Aliases:
 V Status:    Endangered
 Discovered:  November, 1989
 Symptoms:    TSR; .COM, .EXE, .BIN, & .SYS growth; "beeps"
 Origin:      Bulgaria
 Eff Length:  1,206 bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan, F-Prot, Pro-Scan 1.4+, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions: CleanUp V64+, Scan/D/A, F-Prot, VirHunt 2.0+,
              or delete infected files
 General Comments:
       The Vacsina virus is approximately 1200 bytes in length and can
       be found in memory on infected systems.  There are at least 48
       variants of the Vacsina virus, also known as the TP virus
       family, though not all of them have been isolated.  Later versions
       of this virus are included in this listing under the name
       "Yankee Doodle".

       Generally, the Vacsina Virus infects both .COM and .EXE files,
       as well as .SYS and .BIN files.  This virus, when infecting a .EXE
       file, will first convert it into .COM format by changing the MZ
       or ZM identifier in the first two bytes of the file to a JMP
       instruction and then adding a small piece of relocator code, so
       that the .EXE file can be infected as though it were originally a
       .COM file.

       One sign of a Vacsina infection is that programs which have been
       infected may "beep" when executed.  Infected programs will also
       have their date/time in the disk directory changed to the date and
       time they were infected.

       Known Vacsina Variants Include:
       TP04VIR - Infects .EXE files, changing them internally into .COM
                 files.  Infected programs may beep when executed, and
                 may be identified by searching for the text string
                 "VACSINA" along with the second byte from the end of
                 the file containing a 04h.  This version of Vacsina is
                 a poor replicator, and while it will always convert a
                 .EXE file to .COM file format, adding 132 bytes, it does
                 not always infect executed files.
       TP05VIR - Similar to TP04VIR, except that the second to the last
                 byte in the file is now a 05h.  System hangs may also
                 be experienced.
       TP06VIR - Similar to TP05VIR, except the second to the last byte in
                 the file is now a 06h.
       TP16VIR - Similar to TP06VIR, the second to the last byte in the
                 infected file is now 10h.
       TP23VIR - Similar to TP16VIR, the second to the last byte in the
                 infected file is now 17h.  The text "VACSINA" no longer
                 appears in the virus.
       TP24VIR - Similar to TP23VIR, the second to the last byte in the
                 infected file is now 18h.
       TP25VIR - Similar to TP24VIR, the second to the last byte in the
                 infected file is now 19h.

       Also see: Yankee Doodle


 Virus Name:  VComm
 Aliases:     637, Vienna 637
 V Status:    Rare
 Discovered:  December, 1989
 Symptoms:    .EXE growth, TSR, write failures
 Origin:      Poland
 Eff Length:  637 Bytes
 Type Code:   PRaE - Parasitic Resident .EXE Infector
 Detection Method: F-Prot, ViruScan V60+, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: F-Prot, Scan/D, VirexPC, or delete infected files
 General Comments:
       The Vcomm virus is of Polish origin, first isolated in
       December, 1989.  The virus is a .EXE file infector.  When an
       infected file is run, the virus will attempt to infect one
       .EXE file in the current directory.  It will also infect the
       memory resident version of the system's command interpreter.

       When Vcomm infects a file, it first pads the file so that the
       files length is a multiple of 512 bytes, then it adds its
       637 bytes of virus code to the end of the file.

       The memory resident portion of the virus intercepts any
       disk writes that are attempted, and changes them into disk
       reads.


 Virus Name:  VFSI
 Aliases:     437, Happy Day
 V Status:    Rare
 Discovered:  September, 1990
 Symptoms:    .COM growth; message
 Origin:      Bulgaria
 Eff Length:  437 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V71+, Pro-Scan 2.01+
 Removal Instructions: Scan/D, Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The VFSI Virus was isolated in September, 1990 at VFSI (the Higher
       Institute of Financial Management) located in Svistov, a town on the
       Danube.  VFSI is a non-resident, direct action, infector of .COM files,
       including COMMAND.COM.

       When a program infected with the VFSI virus is executed, it will infect
       one other .COM file located in the current directory.  Candidate files
       to be infected are first aligned to be a multiple of 16, and then the
       viral code is added.  Infected files will increase in length by between
       437 and 452 bytes, with the viral code being located at the end of
       infected files.

       Infected files can be easily identified as they will always contain the
       following hex string: 3A483F244B6F636E706C74.

       On approximately one out of five executions of an infected program, the
       program will flash the following message on the screen:

               "HELLO!!! HAPPY DAY and SUCCESS
                  from virus 1.1 VFSI-Svistov"

       This message is encrypted in the viral code, so it is not visible in
       infected files.


 Virus Name:  VHP
 Aliases:     VHP-348, VHP-353, VHP-367, VHP-435
 V Status:    Research
 Discovered:  July 1989
 Symptoms:    .COM growth, system hangs
 Origin:      Bulgaria
 Eff Length:  348 - 435 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V64+, AVTK 3.5+, F-Prot 1.12+, Pro-Scan 2.01+,
              NAV
 Removal Instructions:  Scan/D, F-Prot 1.12+, or Delete infected files
 General Comments:
       The VHP Virus is actually a small group or "family" of viruses that
       was discovered in Bulgaria in early 1990.  There are currently four
       identified variants to the VHP Virus, with the VHP-435 variant being
       the one with the most potential for spreading.  These viruses were
       originally based on the Vienna virus.  The progression of the
       variants shows each variant to be a slightly better replicator.

       The VHP Viruses are:
       VHP-348  : This variant does not replicate due to bugs in the
                  virus code.  If it did replicate, it would infect
                  .COM files.  The virus's effective length is 348 bytes.
       VHP-353  : VHP-348 fixed so that it will infected COMMAND.COM,
                  increasing its size by 353 bytes.  It does not infect
                  other .COM files.  This variant is still buggy, and it
                  will occasionally hang systems when attempting to find
                  a .COM file to infect.
       VHP-367  : VHP-353 which will now infect .COM files besides
                  COMMAND.COM.  Infected files increase in size by 367
                  bytes.  Very rarely, this virus will reinfect an infected
                  .COM file.  VHP-353 does not always infect a .COM file
                  when an infected program is executed, it will sometimes
                  not infect any .COM file, though it has in effect
                  immunized the file from infection.  This effect is
                  probably a bug in this variant.
       VHP-435  : Isolated in July, 1989, this variant is 435 bytes in
                  length and is not destructive, all it does is spread.
                  VHP-435 will attempt to infect 1 file each time an
                  infected program is executed. COMMAND.COM and .EXE
                  files are not infected.  After infecting all of the
                  .COM files on the current drive and directory, it will
                  attempt to infect drive C:.   VHP-435 is the VHP-367
                  virus with some modifications to make it less likely to
                  be noticed.

       Also see: Vienna, VHP2


 Virus Name:  VHP2
 Aliases:     623, VHP-623
 V Status:    Research
 Discovered:  March, 1990
 Symptoms:    .COM growth, reboots or system hangs
 Origin:      Bulgaria
 Eff Length:  623 bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V64+, Pro-Scan 1.4+, AVTK 3.5+, F-Prot 1.12+,
              VirHunt 2.0+, NAV
 Removal Instructions:  Scan/D, Pro-Scan 1.4+, F-Prot 1.12+, or
              Delete infected files
 General Comments:
       The VHP2 Virus was isolated in Bulgaria in March, 1990.  This virus
       is based on the Vienna Virus, and has many of the same characteristics
       of the VHP-435 variant of the VHP virus.  It's major difference is that
       of effective length, and that 1 of every 8 infected programs will
       perform a system warm reboot.

       VHP2 is 623 bytes long, infecting only .COM files but not COMMAND.COM.

       Known variants of the Vienna Virus include:
       VHP-627  : Similar to VHP-623, except that its length is 627 bytes.

       Also see: VHP, Vienna


 Virus Name:  Victor
 Aliases:
 V Status:    Rare
 Discovered:  May, 1990
 Symptoms:    .COM &.EXE growth, data file corruption, file linkage errors,
              and unexpected system reboots
 Origin:      USSR
 Eff Length:  2,458 bytes
 Type Code:   PRAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V63+, Pro-Scan 1.4+, VirexPC, F-Prot 1.12+, NAV,
              IBM Scan 2.00+
 Removal Instructions:  Scan/D, Pro-Scan 1.4+, F-Prot 1.12+, NAV, or
              Delete infected files
 General Comments:
       The Victor Virus was first isolated in May, 1990.  It is believed
       to have originated in the USSR due to messages which appear within
       the viral code:

          "Victor V1.0 The Incredible High Performance Virus
           Enhanced versions available soon.
           This program was imported from USSR.
           Thanks to Ivan."

       The above message can be found at the end of infected files, but
       does not appear to ever be displayed.

       The first time a program infected with the Victor Virus is executed,
       the virus will install itself memory resident, occupying 3,072 bytes
       at the top of free memory.  Interrupt 21 will be intercepted by
       the virus.  After becoming memory resident, Victor will then
       seek out and infect COMMAND.COM.

       Victor is a very slow file infector, only infected approximately
       1 in every 10 programs executed after it becomes memory resident.
       Infected programs will increase in length by between 2,443 and
       2,458 bytes.  The increase in file size is not hidden by the
       virus.

       Occasionally in the process of infecting a file, the virus will
       hang the system, which may result in data file corruption.
       Overlay files may also be infected, resulting in file linkage
       errors.


 Virus Name:  Vienna
 Aliases:     Austrian, Unesco, DOS-62, DOS-68, 1-in-8, 648
 V Status:    Rare
 Discovered:  April, 1988
 Symptoms:    .COM growth; System reboots; System hangs
 Origin:      Austria
 Eff Length:  648 bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan, F-Prot, IBM Scan, Pro-Scan, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV
 Removal Instructions:  CleanUp V66+, VirClean, F-Prot, VirHunt 2.0+,
              Pro-Scan 1.4+, VirexPC, or NAV
 General Comments:
       The Vienna virus was first isolated in April, 1988, in Moscow at
       a UNESCO children's computer summer camp.  The Vienna virus is a
       non-resident, direct action infector of .COM programs, including
       COMMAND.COM.

       When a program infected with the Vienna Virus is executed, the virus
       will select a .COM program in the current directory which as previously
       not been modified by the virus.  Usually, the Vienna Virus will infect
       this file and set the seconds in the file's time in the disk directory
       to 62.  Infected programs will have a file length increase of 648
       bytes with the virus being located at the end of the infected program.

       One out of every six programs which Vienna selects will not be actively
       infected by the virus.  Instead, the first five bytes of the selected
       .COM program will be changed to the hex character string "EAF0FF00F0",
       and the seconds field in the file time will be set to 62.  When these
       programs are later executed, a system warm boot may occur.  Since these
       corrupted programs do not actually contain the Vienna Virus, and most
       anti-viral programs cannot detect them, systems which have been infected
       by Vienna will continue to experience unexpected reboots until all of
       the corrupted .COM programs have been replaced with clean copies.

       Some programs will hang upon execution after they have been infected
       by the Vienna virus.

       The Vienna virus was written by a high school student in Vienna
       Austria as an experiment.  Its large number of variants, as well as
       other viruses which are in part based on Vienna code, can be
       accounted for as its source code has been published many times.

       Due to the large number of variants, Vienna infections may not exhibit
       exactly the symptoms indicated above.

       Known variants of the Vienna Virus include:
       Vienna-B : Similar to Vienna, except that instead of a warm reboot,
                  the program being executed will be deleted.
       Vienna-B 645 : Similar to the Vienna-B variant, this variant's
                  effective length is 645 bytes.  It does not perform either
                  a warm reboot or delete executed programs.  It does,
                  however, infect COMMAND.COM
                  Origin: United States
       Vien6    : Similar to Vienna, except that the warm reboot has been
                  removed.  Effective length of the virus is still 648 bytes.
                  After 7 files have become infected on the current drive,
                  the virus will then start infecting .COM files on drive C:.

       Also see: 1260, Arf, Ghostballs, Grither, Lisbon, W13, VHP, VHP-2,
                 Violator


 Virus Name:  Violator
 Aliases:     Violator Strain B, Violator BT, Violator B1, Violator B2,
              Violator B3
 V Status:    Endangered
 Discovered:  August, 1990
 Symptoms:    .COM growth, Sector not found error on drive B:
 Origin:      USA
 Eff Length:  1,055 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions:  Clean-Up V71+, Scan/D, or Delete infected files
 General Comments:
       The Violator Virus was submitted in August, 1990 by an anonymous
       user of Homebase BBS.  This virus is a non-resident parasitic
       virus which infects .COM files, including COMMAND.COM.

       When a program infected with the Violator Virus is executed, what
       happens depends on what the system date is set to.  If the date is
       prior to August 15, 1990, the virus will infect 1 .COM file located
       in the current directory, adding 1,055 bytes to the program.  If the
       date is August 15, 1990 or after, the virus will not infect any files.

       Symptoms of an infection of the Violator Virus include unexpected
       attempts to access drive B:.  If there is no diskette in drive B:,
       or the diskette in drive B: is write-protected, a Sector not found
       error will result.

       The following message appears in the viral code located in infected
       programs:

           "TransMogrified (TM) 1990 by
            RABID N'tnl Development Corp
            Copyright (c) 1990 RABID!
            Activation Date: 08/15/90
            - Violator Strain B -
            ! (Field Demo Test Version) !
            ! * NOT TO BE DISTRIBUTED * !"

       Known variants of Violator include:
       Violator BT: Very similar to the Violator Virus described above, this
              variant will replicate after August 15, 1990.  It includes the
              same text strings as indicated above for Violator.
       Violator B1: Based on the Violator BT variant, this variant is 716 bytes
              in length.  The major change is that Violator B1 activates on
              September 4, October 4, November 4, and December 4.  On these
              dates, when an infected program is executed it will reformat
              track 0 of all drives.  The only text strings found in this
              variant are:
                    "*.com"
                    "????????COM"
       Violator B2: Violator B2 is a 1,000 byte variant of Violator, and is
              also related to the Arf Virus which appears to have also been
              written by the same group.  Violator B2 will activate on
              October 31 and December 31 when the year is 1990 or later.  At
              that time, it will wipe out the C: drive by overwriting the
              first 700h secotrs with random bytes.  This variant contains
              the text strings:
                    "*.COM"
                    "Arf Arf! Got you!"
                    "????????COM"
                    "-- RABID '90"
                    "down or DIE!"
                    "--- RABID '90"
              Violator B2 infects one or two .COM programs each time an
              infected program is executed, along with displaying the message:
                    "Arf Arf Got you!
                     -- RABID '90"
       Violator B3: Violator B3 is a 843 byte variant of Violator.  Like the
              other Violators, it infects a .COM file each time an infected
              program is executed.  Unlike the other violators, it will also
              affect the C: drive, overwriting the boot sector and file
              allocation table immediately in some circumstances.  Damage
              caused by Violator B3 can be fixed with Norton Disk Doctor.
              Violator B3 should activate on December 25, at which time it will
              attempt to format the current drive.  Text strings found in
              Violator B3 are:
                    "Violator Strain B3 - RABID Nat'nl Development Corp."
                    "*.COM"

       Also see: Arf, Vienna, Violator B4


 Virus Name:  Violator B4
 Aliases:     Christmas Violator, Violator Strain B4
 V Status:    Rare
 Discovered:  December, 1990
 Symptoms:    .COM growth on 8088 based system;
              Hard Disk Corruption on 80286 & 80386 based systems
 Origin:      United States
 Eff Length:  5,302 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method:  ViruScan V74+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Violator B4 Virus was isolated in December, 1990 in the United
       States.  This virus was originally released into the public domain
       on a trojan version of DSZ (DSZ1203).  It is a non-resident infector
       of .COM files, including COMMAND.COM.

       What Violator B4 does depends on what processor is in the personal
       computer it is being executed on.  On 80286 and above processors, the
       virus will activate immediately, overwriting the beginning portion of
       the system hard disk.  It will also attempt to display a Christmas
       greeting at that time, but the greeting display will be garbled if
       Ansi.Sys is not loaded.  Damage caused by Violator B4 at activation
       can be repaired using Norton Disk Doctor.

       On an 8088 based system, Violator B4 will do nothing but replicate.
       Each time an infected program is executed, the virus will infect one
       other .COM program in the current directory.  Violator B4 infected
       files will have a file length increase of 5,302 bytes.  The file's
       date and time in the disk directory will not be altered.  The virus
       will be located at the end of the infected file.

       The following text message is contained within the Violator B4 virus,
       though it is never displayed:

          "Violator Strain B4 - Written by RABID Nat'nl Development Corp.
           RABID would like to take this opportunity to extend it's sincerest
           holiday wishes to all Pir8 lamers around the world! If you are
           reading this, then you are lame!!!
           Anyway, to John McAffe! Have a Merry Christmas and a virus filled
           new year. Go ahead! Make our day!
           Remember! In the festive season, Say No to drugs!!! They suck shit!
           (Bah! We make a virus this large, might as well have
           something positive!)"

       Known variants of Violator B4 include:
       Violator B4-1: Very similar to the original Violator B4 described
               above, this variant will overwrite track 1 of the system
               hard disk after it has completed two infections on a 386-based
               machine.  It contains the same text messages as the Violator
               B4 Virus described above, and only differs by a few bytes.
       Violator B4-B: This virus is the same as Violator B4-1, it differs by
               two bytes.  Its behavior is identical to Violator B4-1.

       Also see:  Vienna, Violator


 Virus Name:  VirDem
 Aliases:     VirDem 2
 V Status:    Endangered
 Discovered:  1986-1987
 Symptoms:    .COM growth, Messages
 Origin:      Germany
 Eff Length:  1,236 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method:  VirexPC, AVTK 3.5+, F-Prot 1.12+, ViruScan V71+,
              VirHunt 2.0+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions:  F-Prot 1.12+, Scan/D, or Delete infected files
 General Comments:
       The VirDem Virus was written in 1986-1987 by Ralf Burger of Germany.
       The virus was originally distributed in Europe as a demonstration
       virus, to assist computer users in understanding how a computer
       virus operates.

       The VirDem virus is not memory resident, and only infects .COM files
       on the A: drive.  It will always skip the first .COM file in the
       root directory, so normally it will not infect COMMAND.COM.  It will
       also not infect .COM files past the second subdirectory on the disk.

       Infected files that were originally less than approximately 1,500
       bytes will be 2,616 bytes after infection.  .COM files which were
       greater than 1,500 bytes will increase in size by approximately
       1,236 bytes.

       When an infected program is executed, VirDem will infect the next
       candidate .COM file.  Infected files will contain the viral code,
       followed by the original program.  After infecting the .COM file,
       the virus will play a "game" with you, starting with the following
       text being displayed:

              " VirDem Ver.: 1.06 (Generation #) aktive.
                Copyright by R.Burger 1986,1987
                Phone.: D - xxxxx/xxxx

                This is a demoprogram for
                computerviruses. Please put in a
                number now.
                If you're right, you'll be
                able to continue.
                The number is between
                0 and #                                         "

               (Note: I have removed the phone number here, but it
                appears where xxxxx/xxxx is above.  Where # is, the
                virus's generation number appears.)

       At this point, you must guess the correct number and enter it.  If
       you put in the wrong number, you get the following message and
       your program is not run:

              " Sorry, you're wrong

                More luck at next try ....    "

       If you guess the correct number, you receive the following message
       and your program then executes:

              " Famous. You're right.
                You'll be able to continue.  "

       Finally, after all the candidate .COM files on the A: drive are
       infected, the following message is displayed:

              " All your programs are
                struck by VIRDEM.COM now."

       VIRDEM.COM was the original distribution file containing the virus,
       and had a VIRDEM.DOC file included with it.  VirDem is not widespread,
       and is not destructive.

       Known variant(s) of VirDem include:
       VirDem 2 : Similar to the virus described above, the major difference
                  is that the text messages have been translated to German.

       Also see: Burger


 Virus Name:  Virus-90
 Aliases:
 V Status:    Research
 Discovered:  December, 1989
 Symptoms:    .COM growth, TSR
 Origin:      District of Columbia, USA
 Eff Length:  857 bytes
 Type Code:   PRC - Parasitic Resident .COM Infector
 Detection Method:  ViruScan/X V67+, F-Prot, IBM Scan, Pro-Scan 1.4+, VirexPC,
              AVTK 3.5+, NAV
 Removal Instructions:  Scan/D/X, F-Prot, Pro-Scan 1.4+,
              or delete infected files
 General Comments:
       The Virus-90 virus was originally distributed in December, 1989
       by Patrick Toulme as an "educational tool", with the virus
       source also available for sale.  In January, 1990, the
       author contacted the sites where he had uploaded the virus
       requesting that they remove it from their systems, his having
       decided a live virus was not a "good idea" for an educational
       tool after being contacted by several viral authorities.

       The following description was submitted by Patrick Toulme in
       November 1990 for inclusion in this listing:

       "This educational, research virus was written by Patrick Toulme
       to aid developers in understanding direct-virus action and in
       creating virus-resistant software.  This virus is a simple COM
       infector that will not infect a hard drive and advises the user
       when a file on a floppy disk is to be infected.  Of course, no
       damage occurs from the virus and all infected files advise the
       user of the infection upon execution.  The safeguards provided by
       the author prevent accidental infection and the dis-assembly of the
       code is extremely difficult.  Upon request from the anti-viral
       community, Virus-90 is now only available to approved anti-virus
       researchers."

       Also see: Virus101


 Virus Name:  Virus101
 Aliases:
 V Status:    Research
 Discovered:  January, 1990
 Symptoms:    TSR, BSC, .COM growth (floppy only)
 Origin:      District of Columbia, USA
 Eff Length:  2,560 Bytes
 Type Code:   PRAFK - Parasitic Resident Infector
 Detection Method: ViruScan/X V67+, Pro-Scan 1.4+, F-Prot 1.12+, VirHunt 2.0+,
              NAV
 Removal Instructions:  Scan/D/X or delete infected files
 General Comments:
       The Virus101 is the "big brother" of Virus-90, also written by
       Patrick Toulme as an "educational tool" in January 1990.
       This virus is memory resident, and employs an encryption scheme
       to avoid detection on files.  It infects COMMAND.COM, and all
       other executable file types.  Once it has infected all the
       files on a diskette, it will infect the diskette's boot
       sector.  It only infects floppy diskettes in its current
       version.

       The following description was submitted by Patrick Toulme for
       inclusion in this listing in November 1990:

       "Virus-101 is a sophisticated, continually encrypting, research
       virus written by Patrick Toulme, author of Virus-90.  Virus-101
       infects both COM and EXE files and will evade most anti-virus
       software and will continually encrypt itself to prevent
       non-algorithmic search scans.  This virus is not available to the
       general public and is presently used by government agencies and
       corporate security departments to test anti-virus software and
       hardware devices."

       Also see: Virus-90


 Virus Name:  Voronezh
 Aliases:
 V Status:    Rare
 Discovered:  December 1990
 Symptoms:    .COM & .EXE growth; decrease in total system and available memory
 Origin:      USSR
 Eff Length:  1,600 Bytes
 Type Code:   PRhA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V74+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Voronezh Virus was received in December, 1990.  It is originally
       from the USSR.  Voronezh is a memory resident infector of .COM and
       .EXE files, and does not infect COMMAND.COM.

       The first time a program infected with Voronezh is executed the virus
       will install itself memory resident.  This virus will be resident at
       the top of system memory but below the 640K DOS boundary.  While the
       virus reserves 3,744 bytes of memory for itself, it does not move the
       interrupt 12 return.  Interrupt 21 will be hooked by the virus.  This
       virus may also reserve 24 bytes of display memory on the display
       adapter card.

       After Voronezh is memory resident, .COM and .EXE files will be
       infected when they are executed.  Infected files will increase in
       length by 1,600 bytes, the virus will be located at the end of
       infected programs.  Infected programs will also contain the
       text string:

               "Voronezh,1990 2.01".

       It is unknown if this virus does anything besides replicate.

       Known variant(s) of Voronezh are:
       Voronezh B: Similar to the Voronezh Virus described above, the major
               difference with Voronezh B is that Voronezh B will infect files
               when they are executed or openned for any reason.  The original
               virus did not infect on file open.  The text string indicated
               for Voronezh is also found in this variant.


 Virus Name:  VP
 Aliases:
 V Status:    Rare
 Discovered:  May 1990
 Symptoms:    COMMAND.COM & .COM file growth, system slowdown
 Origin:      England
 Eff Length:  913 Bytes
 Type Code:   PNCK - Parasitic Non-Resident .COM Infector
 Detection Method: ViruScan V64+, Pro-Scan 1.4+, AVTK 3.5+, F-Prot 1.12+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions:  Scan/D, Pro-Scan 1.4+, F-Prot 1.12+, VirHunt 2.0+, or
              Delete infected files
 General Comments:
       The VP Virus was first isolated in May, 1990.  It is a non-resident
       generic .COM infector, and will infect COMMAND.COM.  When an
       infected program is run, the virus will attempt to locate and
       infect another .COM file.  In some cases, such as COMMAND.COM, the
       virus will display the contents of the program being infected.  In
       other cases, the virus may attempt to execute the program being
       infected.  Infected files increase in length by 913 bytes, and
       can be identified as the following hex string will appear near both
       the beginning and the end of an infected program: '4503EB1808655650'.


 Virus Name:  Vriest
 Aliases:
 V Status:    New
 Discovered:  April, 1991
 Symptoms:    .COM growth; TSR
 Origin:      Europe
 Eff Length:  1,280 Bytes
 Type Code:   PRsCK - Parasitic Resident .COM Infector
 Detection Method:
 Removal Instructions:  Delete Infected Files
 General Comments:
       The Vriest Virus was received in April, 1991 and is believed to be
       from somewhere in Europe.  Vriest is a memory resident infector of
       .COM files including COMMAND.COM.

       The first time a program infected with Vriest is executed, Vriest will
       become memory resident as a low system memory TSR of 1,584 bytes.
       Interrupts 20, 21, and 27 will be hooked by the virus.

       Unlike most virus, Vriest will not infect programs when they are
       executed or openned.  It only infects .COM files when they are copied,
       at which time the target file will become infected.

       Programs infected with Vriest will increase in size by 1,280 bytes.
       The virus will be located at the beginning of the infected file.  The
       file's date and time in the DOS disk directory will not have been
       altered.

       Vriest infected programs may become reinfected, adding an additional
       1,280 bytes to the file length.  These reinfections occur when an
       infected program is again copied.

       Vriest does not appear to do anything besides replicate.


 Virus Name:  W13
 Aliases:     Toothless Virus, W13-A
 V Status:    Endangered
 Discovered:  December, 1989
 Symptoms:    .COM growth
 Origin:      Poland
 Eff Length:  534 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method: ViruScan V63+, F-Prot, IBM Scan, Pro-Scan 1.4+, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions:  Scan/D, F-Prot, Pro-Scan 1.4+, VirHunt 2.0+, NAV,
              or delete infected files
 General Comments:
       The W13 virus is a .COM file infector that doesn't do much
       except for infect files.  The virus was isolated in December
       1989 in Poland.

       While W13 is based on the Vienna virus, it does not damage files
       or have some of the other side effects of the Vienna virus.  It
       contains a number of bugs which prevent it from being a good
       replicator.

       Known variant(s) of W13 include:
       W13-B     : The original W13 Virus with several bugs fixed.  This
                   variants length is 507 bytes instead of 534 bytes.


 Virus Name:  Westwood
 Aliases:
 V Status:    Rare
 Discovered:  August, 1990
 Symptoms:    .COM & .EXE growth; TSR; system slowdown; black window;
              file deletion on Friday The 13ths
 Origin:      Westwood, California, USA
 Eff Length:  1,819 - 1,829 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method: ViruScan V67+, F-Prot 1.12+, Pro-Scan 2.01+, NAV,
              IBM Scan 2.00+
 Removal Instructions:  Scan/D, CleanUp, NAV, or Delete infected files
 General Comments:
       The Westwood Virus was isolated in August, 1990 in Westwood, California.
       This virus is a substantially altered variant of the Jerusalem B virus,
       enough so that all anti-virals tested which could detect Jerusalem B
       were unable to identify it.  Like Jerusalem, it infects .COM, .EXE, and
       overlay files, but not COMMAND.COM.

       The first time a program infected with the Westwood virus is executed,
       the virus will install itself memory resident as a low system memory
       TSR of 1,808 bytes.  Interrupts 8 and 21 will be hooked.  If the
       system date happens to be a Friday The 13th, interrupt 22 will also
       be hooked.

       After the virus is memory resident, any program which is executed
       will become infected with the Westwood virus.  .COM files will
       increase by 1,829 bytes with the virus's code located at the beginning
       of the infected program.  .EXE files and overlay files are infected
       with the virus's code added to the end of the program.  .EXE files
       increase in length by between 1,819 and 1,829 bytes.  Unlike most
       variants of the Jerusalem virus, Westwood does not reinfect .EXE files.

       Infected systems will experience a system slowdown occurring after
       the virus has been memory resident for 30 minutes.  At this time, the
       "black window" or "black box" common to the Jerusalem virus will
       appear on the lower left hand side of the system display.  Screen
       contain around the area of the "box" may be corrupted if screen writes
       happened to be occurring when the box appeared.

       On Friday The 13ths, the Westwood Virus will delete any programs that
       are executed once the virus becomes memory resident.

       Also see: Jerusalem B


 Virus Name:  Whale
 Aliases:     Mother Fish, Stealth Virus, Z The Whale
 V Status:    Research
 Discovered:  August, 1990
 Symptoms:    .COM & .EXE growth; decrease in available memory;
              system slowdown; video flicker; slow screen writes;
              file allocation errors; simulated system reboot
 Origin:      Hamburg, West Germany
 Eff Length:  9,216 Bytes
 Type Code:   PRhA - Parasitic Resident .COM & .EXE Infector
 Detection Method: ViruScan V67+, Pro-Scan 2.01+, NAV, IBM Scan 2.00+
 Removal Instructions:  Scan/D, CleanUp V67+, Pro-Scan 2.01+,
              or Delete infected files
 General Comments:
       The Whale Virus was submitted in early September, 1990.  This virus
       had been rumored to exist since the isolation of the Fish 6 Virus in
       June, 1990.  It has been referred to by several names besides Whale,
       including Mother Fish and Z The Whale.  The origin of this virus is
       subject to some speculation, though it is probably from Hamburg,
       West Germany due to a reference within the viral code once it is
       decrypted.

       The first time a program infected with the Whale Virus is executed,
       the Whale will install itself memory resident in high system memory
       but below the 640K DOS boundary.  On the author's XT clone, the
       virus always starts at address 9D90.  Available free memory will
       be decreased by 9,984 bytes.  Most utilities which display memory
       usage will also indicate a value for total system memory which is
       9,984 bytes less than what is actually installed.

       The following text string can be found in memory on systems
       infected with the Whale virus:

              "Z THE WHALE".

       Immediately upon becoming memory resident, the system user will
       experience the system slowing down.  Noticeable effects of the
       system slowdown include video flicker to extremely slow screen
       writes.  Some programs may appear to "hang", though they will
       eventually execute properly in most cases since the "hang" is due
       to the slowing of the system.

       When a program is executed with the Whale memory resident, the virus
       will infect the program.  Infected programs increase in length, the
       actual change in length is usually 9,216 bytes.  Note the "usually":
       this virus does occasionally infect a program with a "mutant" which
       will be a different length.  If the file length increase is exactly
       9,216 bytes, the Whale will hide the change in file length when a
       disk directory command is executed.  If the file length of the viral
       code added to the program is other than 9,216 bytes, the file length
       displayed with the directory command will either the actual infected
       file length, or the actual infected file length minus 9,216 bytes.

       Executing the DOS CHKDSK program on infected systems will result in
       file allocation errors being reported.  If CHKDSK /F is executed,
       file damage will result.

       The Whale also alters the program's date/time in the directory when
       the file is executed, though it is not set to the system date/time
       of infection.  Occasionally, Whale will alter the directory entry
       for the program it is infecting improperly, resulting in the directory
       entry becoming invalid.  These programs with invalid directory
       entries will appear when the directory is listed, but some disk
       utilities will not allow access to the program.  In these cases, the
       directory entry can be fixed with Norton Utilities FD command to
       reset the file date.

       The Whale occasionally will change its behavior while it is memory
       resident.  While most of the time it only infects files when
       executed, there are periods of time when it will infect any file
       opened for any reason.  It will also, at times, disinfect files
       when they are copied with the DOS copy command, at other times it
       will not "disinfect on the fly".

       Occasionally, the Whale Virus will simulate what appears to be a
       system reboot.  While this doesn't always occur, when it does occur
       the Break key is disabled so that the user cannot exit unexpectedly
       from the execution of the system's AutoExec.Bat file.  If the
       AutoExec.Bat file contained any software which does file opens of
       other executable programs, those opened executable programs will
       be infected at that time if they were not previously infected.
       Typically, files infected in this manner will increase by 9,216
       bytes though it will not be shown in a directory listing.

       A hidden file may be found in the root directory of drive C: on
       infected files.  This file is not always present, the virus will
       sometimes remove it, only to recreate it again at a later time.
       The name of this hidden file is FISH-#9.TBL, it contains an
       image of the hard disk's partition table along with the following
       message:

               "Fish Virus #9
                A Whale is no Fish!
                Mind her Mutant Fish
                and the hidden Fish Eggs
                for they are damaging.
                The sixth Fish mutates
                only if the Whale is in
                her Cave."

       After the discovery of this hidden file, the author of this
       document made several attempt to have the Fish 6 Virus mutate
       by introducing it and Whale into a system.  Under no circumstances
       did a mutation of either virus result, the resultant files were
       infected with both an identifiable Fish 6 infection and a Whale
       infection.

       Whale is hostile to debuggers and contains many traps to prevent
       successful decryption of the virus.  One of its "traps" is to lock
       out the keyboard if it determines a debugger is in use.


 Virus Name:  Wisconsin
 Aliases:     Death To Pascal
 V Status:    Rare
 Discovered:  September, 1990
 Symptoms:    .COM growth; Message; Write Protect Errors; .PAS files
              disappear; file date/time changes
 Origin:      Wisconsin, USA
 Eff Length:  825 Bytes
 Type Code:   PNC - Parasitic Non-Resident .COM Infector
 Detection Method: ViruScan V67+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions:  Scan/D, or Delete infected files
 General Comments:
       The Wisconsin Virus was received in September, 1990.  The origin of
       the sample was Wisconsin, which is where its name came from.  It is
       also reported to have been isolated at about this same time in
       California.  Wisconsin is a non-resident infector of .COM files, but
       it does not infect COMMAND.COM.

       When a program infected with the Wisconsin Virus is executed, the virus
       will alter the date and time of the program being executed to the
       current system date and time.  The Wisconsin Virus will then infect
       one other .COM file in the current directory.  Infected files will
       increase in length by 825 bytes, with the viral code located at the
       beginning of the file.

       If an attempt is made to execute a program infected with the Wisconsin
       virus from a write-protected diskette, a write protect error will
       occur.  This virus does not intercept this error.

       Infected programs may display the following message:

               "Death to Pascal."

       When this message is displayed, any .PAS files located in the
       current directory will be deleted.  This message cannot be seen in
       infected files as it is encrypted.


 Virus Name:  Wolfman
 Aliases:
 V Status:    Rare
 Discovered:  July, 1990
 Symptoms:    TSR; .COM & .EXE growth
 Origin:      Taiwan
 Eff Length:  2,064 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V66+, Pro-Scan 2.01+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Wolfman Virus was discovered in Taiwan in July, 1990.  It is a
       memory resident generic infector of .COM and .EXE files, but not
       COMMAND.COM.

       The first time a program infected with the Wolfman Virus is executed,
       the virus will install itself memory resident as a TSR with 2 blocks
       of memory reserved.  The first block of memory reserved is 68,032
       bytes in length, the second block of reserved memory is 4,544 bytes
       in length.  The total 72,640 bytes of memory is in low system memory,
       and available free memory is decreased by a corresponding amount.
       The virus hooks interrupts 09, 10, 16, 21, 2F, ED, and F5.

       Once the virus is memory resident, the virus will infect any .COM or
       .EXE file which is executed if the pre-infection file length is
       greater than or equal to 2,064 bytes.  Infected files increase in
       length by 2,064 bytes.  .COM files which are infected will have the
       virus's code located at the beginning of the .COM file, .EXE files
       will have the virus located at the end.  Infected files will have
       their date and time in the disk directory altered to the system
       date and time when infection occurred.

       It is unknown when Wolfman activates, or if it is destructive.

       Known variant(s) of Wolfman include:
       Wolfman 2: This variant is fairly similar to the Wolfman Virus.  Its
                  memory resident TSR is 67,984 bytes, and it hooks interrupts
                  09, 10, 16, 21, CF, D1, D3, and several others.  Files
                  smaller than 5,120 bytes will not be infected by the virus.
                  Infected .EXE files will contain the text string "WOlf_mAN",
                  though this string cannot be found in infected .COM programs
                  as it will be encrypted.


 Virus Name:  Yankee Doodle
 Aliases:     TP44VIR, Five O'clock Virus
 V Status:    Common - Europe
 Discovered:  September, 1989
 Symptoms:    .COM & .EXE growth, melody @ 5 p.m.
 Origin:      Austria or Bulgaria
 Eff Length:  2,885 or 2,899 Bytes
 Type Code:   PRsA - Parasitic Resident .COM & .EXE Infector
 Detection Method:  ViruScan V42+, F-Prot, IBM Scan, Pro-Scan, VirexPC,
              AVTK 3.5+, VirHunt 2.0+, NAV
 Removal Instructions: CleanUp V64+, Scan/D, VirClean, F-Prot, NAV, or
              delete infected files
 General Comments:
       The Yankee Doodle virus was isolated by Alexander Holy of
       the North Atlantic Project in Vienna, Austria, on
       September 30, 1989.  It was also isolated in Bulgaria shortly
       thereafter, where it is known as TP44VIR.

       This virus is a parasitic virus which infects both .COM and .EXE
       files, and installs itself memory resident.  After installing itself
       memory resident, it will play Yankee Doodle on the system speaker at
       17:00.  Infected programs will be increased in length by 2,899 bytes.

       Other than being disruptive by playing Yankee Doodle, this
       virus currently does nothing else harmful besides infecting
       files.

       As a side note, some variants of the Yankee Doodle Virus will seek
       out and modify Ping Pong viruses, changing them so that they self-
       destruct after 100 infections.

       Known variants of the Yankee Doodle Virus are:
       TP33VIR - This variant disables interrupts 1 and 3, thus interfering
                 with using debuggers to isolate it.  The behavior of the
                 virus also has been changed so that it infected programs
                 will play Yankee Doodle at 5PM.  The second to the last
                 byte in infected files is the virus's "version number",
                 in the case of TP33VIR, it is 21h (33 in hex).
       TP34VIR - Similar to TP33VIR, except that this variant is memory
                 resident, and infects programs as they are executed.
                 The second to the last byte in infected files is 22h.
       TP38VIR - Similar to TP34VIR, except that .COM and .EXE files are
                 handled in a different way, and this variant will
                 disinfect itself if it is loaded with CodeView active in
                 memory.  The second to the last byte in infected files
                 is 26h.  TP38VIR was first isolated in Bulgaria in
                 July 1988, and is the oldest virus known in Bulgaria.
       TP41VIR - Similar to TP38VIR, except the second to the last byte
                 in infected files is 29h.
       TP42VIR - This variant of Vacsina tests to determine if the system
                 is infected with the Ping Pong virus, and if it is, will
                 attempt to disable the Ping Pong virus by modifying it.
                 The second to the last byte in infected files is now 2Ah.
       TP44VIR - Similar to TP42VIR, the second to the last byte of infected
                 files is 2Ch.
       TP45VIR - Similar to TP44VIR, the second to the last byte of infected
                 files is 2Dh.
       TP46VIR - Similar to TP45VIR, except that this variant can detect
                 and kill the Cascade (1701) Virus.  The second to the last
                 byte of infected files is now 2Eh.
       Yankee Doodle-B: Very similar to the Yankee Doodle virus, except
                 the length of the viral code is 2,772 bytes.

       Also see: Vacsina


 Virus Name:  Yankee 2
 Aliases:     Yankee Virus, Yankee-go-Home, 1961
 V Status:    Endangered
 Discovered:  September, 1989
 Symptoms:    .EXE growth, Yankee Doodle
 Origin:      Bulgaria
 Eff Length:  1,961 Bytes
 Type Code:   PNE - Parasitic Non-Resident .EXE Infector
 Detection Method:  ViruScan V62+, Virex PC, AVTK 3.5+, VirHunt 2.0+, NAV,
              IBM Scan 2.00+
 Removal Instructions: Scan/D, or delete infected files
 General Comments:
       The Yankee 2, or Yankee Virus, was isolated in Bulgaria
       in 1989.  Unlike the Yankee Doodle Virus, the Yankee 2
       Virus is not memory resident.  It also only infects .EXE files,
       adding 1,961 bytes to their length.  The virus will attempt to
       infect an .EXE file in the current directory whenever an
       infected program is executed.  If it is successful in locating
       an uninfected .EXE file, and infects it, Yankee Doodle will be
       played on the system speaker.  Infected files will have the
       hex string '6D6F746865726675636B6572' at the end.

       The Yankee 2 Virus will not infect CodeView.

       Known variant(s) of the Yankee 2 virus are:
       1624    - This variant is similar to Yankee 2 in function, the major
                 change is that its effective length is 1,624 bytes.

       Also see: Enigma


 Virus Name:  Yap Virus
 Aliases:
 V Status:    Rare
 Discovered:  March, 1991
 Symptoms:    .COM growth; TSR; "Bugs" may appear in screen;
              Decrease in available free memory
 Origin:      USA
 Eff Length:  6,258 Bytes
 Type Code:   PRsCK - Parasitic Resident .COM Infector
 Detection Method: ViruScan V75+
 Removal Instructions: Scan/D, or Delete infected files
 General Comments:
       The Yap Virus was discovered in March, 1991, in the United States.
       Yap is a memory resident .COM file infector.  It will infect
       COMMAND.COM.

       The first time a program infected with the Yap Virus is executed, the
       virus will install itself memory resident as a low system memory TSR
       of 11,344 bytes.  Interrupts 09 and 21 will be hooked by the virus.

       After Yap is memory resident, it will infect .COM programs as they
       are executed.  If COMMAND.COM is executed, it will become infected.
       .COM Programs infected with Yap will increase in size by 6,258 bytes.
       The virus will be located at the end of infected programs.  The file's
       date and time in the disk directory will not be altered.

       With the Yap Virus memory resident, if the system user holds down the
       ALT key, or presses the ALT key and another key in combination,
       numerous graphic "bugs" will appear on the screen which will eat the
       contents of the system display.  Pressing the ALT key, or ALT key
       combination, again will result in the system's display being restored.

       Yap is an encrypted virus, using encryption very similar to that
       employed by the Cascade Virus and its variants.


 Virus Name:  Yukon Overwriting
 Aliases:
 V Status:    Rare
 Discovered:  January, 1991
 Symptoms:    Divide Overflow errors; Beginning of Programs Overwritten
 Origin:      Canada
 Eff Length:  151 Bytes
 Type Code:   ONCK - Overwriting Non-Resident .COM Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The Yukon Overwriting Virus was isolated in January, 1991 in Canada.
       This virus is a non-resident overwriting virus that infects .COM files,
       including COMMAND.COM.

       When a program infected with the Yukon Overwriting Virus is executed,
       the virus will infect all .COM programs in the current directory.
       Infected programs will have the first 151 bytes of the program
       overwritten with the virus.  Their date and time in the disk directory
       will not be altered in the process of infection.

       After infecting all of the .COM files in the current directory, the
       program the user was attempting to execute will fail with a Divide
       Overflow error.

       Infected programs can be easily identified because the text string
       Divide Overflow$ will be located beginning at offset 87h within the
       infected program.

       Programs infected with the Yukon Overwriting Virus cannot be
       disinfected as the portion overwritten by the virus is not stored.
       Infected programs must be deleted and replaced with uninfected copies.


 Virus Name:  Zero Bug
 Aliases:     Palette, 1536
 V Status:    Endangered
 Discovered:  September, 1989
 Symptoms:    .COM growth (see text), TSR, graphics display
 Origin:      Netherlands
 Eff Length:  1,536 bytes
 Type Code:   PRsC - Parasitic Resident .COM Infector
 Detection Method:  Viruscan/X V67+, F-Prot, Pro-Scan 1.4+, VirexPC, AVTK 3.5+,
              VirHunt 2.0+, NAV, IBM Scan 2.00+
 Removal Instructions: Scan/D/X, CleanUp V66+, F-Prot, Pro-Scan 1.4+,
              VirHunt 2.0+, or delete infected files
 General Comments:
       The Zero Bug virus was first isolated in the Netherlands by
       Jan Terpstra in September, 1989.  This virus is a memory
       resident .COM file infector.  Infected .COM files will
       increase in size by 1,536 bytes, however the increase in file
       length will not show up when the disk directory is displayed.

       The virus's main objective is to infect the copy of
       COMMAND.COM indicated by the environment variable COMSPEC.
       If COMSPEC doesn't point to anything, the Zero Bug virus will
       install itself memory resident using INT 21h.

       After the virus has either infected COMMAND.COM or become
       memory resident, it will infect all .COM files that are
       accessed, including those accessed by actions such as COPY or
       XCOPY.  Any .COM file created on an infected system will also
       be infected.

       If the currently loaded COMMAND.COM is infected, the virus
       will hook into the timer interrupt 1Ch, and after a certain
       amount of time has past, a smiley face character (ASCII 01)
       will appear and eat all the zeros it can find on the screen.
       The virus does not delete files or format disks in its present
       form.


 Virus Name:  ZeroHunt
 Aliases:     Minnow, Stealth
 V Status:    Research
 Discovered:  December, 1990
 Symptoms:    Internal changes to COM files
 Origin:      USA
 Eff Length:  416 Bytes
 Type Code:   PRCK - Parasitic Overwriting .COM Infector
 Detection Method:  Viruscan V72+, Pro-Scan 2.01+, IBM Scan 2.00+
 Removal Instructions: Scan/D, Pro-Scan 2.01+, or Delete infected files
 General Comments:
       The ZeroHunt, or Minnow, Virus was submitted in December, 1990 by
       Paul Ferguson of Washington, DC.  ZeroHunt is a memory resident
       overwriting infector of COM files, including COMMAND.COM.  This virus
       is classified as a Stealth Virus.

       When the first program infected with the ZeroHunt Virus is executed,
       the virus will install itself memory resident in the command environment
       area.  It occupies approximately 200 bytes of memory and hooks a number
       of interrupts, including interrupt 21 by remapping.

       Once ZeroHunt is memory resident, it waits for a COM file to be openned
       or executed which contains 416 or more bytes of 00h characters.  These
       characters usually are stack space in the file, and most commonly occur
       in EXE files which have been converted to COM files.  If the candidate
       COM file contains enough 00h characters, ZeroHunt will infect the file
       by writing its viral code over the first 416 bytes of the 00h characters.
       ZeroHunt then alters the first four bytes of the newly infected file so
       that upon execution its viral code will execute first.

       Like other Stealth class viruses, ZeroHunt will disinfect the file on
       the fly, so that the virus cannot be detected in files if it is memory
       resident.  Since infected files have been infected internally by over-
       writing stack space, there will be no change in infected file length.

       ZeroHunt carries no activation criteria at the present time, it just
       replicates.

       Known variant(s) of ZeroHunt include:
       ZeroHunt B: Based on the ZeroHunt virus, this variant becomes memory
                   resident in 1,408 bytes of reserved low system memory.  It
                   hooks interrupts 21, 25, 26, and several others.  It
                   infects .COM programs when they are executed provided that
                   a block of at least 411 bytes of binary zeros can be found
                   within the candidate program.  If the block is found, then
                   the virus will overwrite the last 411 bytes of binary
                   zeros in the block, and alter the first four characters of
                   the program so that the viral code will be executed first.


 Virus Name:  ZK900
 Aliases:     Pray
 V Status:    Rare
 Discovered:  April, 1991
 Symptoms:    .COM & .EXE growth; Decrease in total system & available memory;
              Music
 Origin:      USA
 Eff Length:  900 Bytes
 Type Code:   PRhAK - Parasitic Resident .COM & .EXE Infector
 Detection Method:
 Removal Instructions: Delete infected files
 General Comments:
       The ZK900 Virus was received in April, 1991, from David Chess of IBM.
       ZK900 is a memory resident .COM and .EXE infector, and will infect
       COMMAND.COM.

       The first time a program infected with ZK900 is executed, the virus
       will install itself memory resident at the top of system memory but
       below the 640K DOS boundary.  Interrupts 1C and 21 will be hooked by
       the virus.

       After becoming memory resident, ZK900 will infect .COM and .EXE
       programs as they are executed.  If COMMAND.COM is executed, it will
       become infected.  Infected programs will increase in size by 900 bytes
       with the virus being located at the end of the file.  The program's
       date and time in the disk directory will not be altered by the virus.
       Infected programs will end with the text characters "zx".

       Systems infected with ZK900 may experience a tune being played every
       three to five minutes on the system speaker.  The tune is the children's
       rhyme "Pray for the dead, and the dead will pray for you".


-------------------------------------------------------------------------------

                         Virus Information Summary List
                        Virus Common Name Cross-Reference

 The following is a cross-reference of common virus names back to
 the name they are listed by in the virus information section.
 Hopefully, this cross-reference will alleviate some confusion when
 different anti-viral software packages refer to different names for
 the same virus.

 Virus Name              Refer To Virus(es) In VirusSum.Doc:
 ----------------------  -----------------------------------------------
 @ Virus                 Turbo 448
 62-B                    Vienna
 100 Years Virus         4096
 163 COM Virus           Tiny Virus
 217                     Polish 217
 333                     Kennedy
 382                     382 Recovery Virus
 382 Recovery Virus      382 Recovery Virus
 405                     405
 437                     VFSI
 453                     RPVS
 500 Virus               Golden Gate
 505                     Burger
 509                     Burger
 512                     512
 512-A                   512
 512-B                   512
 512-C                   512
 512-D                   512
 512-E                   512
 512-F                   512
 512 Virus               Friday The 13th COM Virus
 529                     Polish 529
 541                     Burger
 555                     Dutch 555
 623                     VHP2
 632                     Saratoga
 637                     Vcomm
 642                     Icelandic
 646                     646
 648                     Vienna
 765                     Perfume
 834 Virus               834 Virus
 834-B                   834 Virus
 867                     Typo COM
 903                     903
 903-B                   903
 944                     Dot Killer
 1008                    1008
 1022                    Fellowship
 1024-B                  Nomenklatura
 1075                    Crash
 1168                    Datacrime-B
 1210                    1210
 1226                    1226
 1226D                   1226D
 1226M                   1226D
 1253                    1253
 1260                    1260
 1280                    Datacrime
 1374                    Little Pieces
 1381 Virus              1381 Virus
 1381-B                  1381 Virus
 1392                    1392
 1514                    Datacrime II
 1536                    Zero Bug
 1539                    Christmas Virus
 1554                    1554
 1559                    1554
 1575                    1575
 1575-B                  1575
 1575-C                  1575
 1577                    1575
 1591                    1575
 1605                    1605
 1605-B                  1605
 1624                    Yankee 2
 1701                    Cascade
 1704                    Cascade, Cascade-B
 1704 Format             1704 Format
 1704-B                  Cascade B
 1720                    1720
 17Y4                    Cascade
 1808                    Jerusalem
 1813                    Jerusalem
 1917                    Datacrime IIB
 1961                    Yankee 2
 1971                    Eight Tunes
 2080                    Fu Manchu
 2086                    Fu Manchu
 2100                    V2100
 2131                    2131
 2480                    Crew-2480
 2560                    2560
 2576                    Taiwan 4
 2930                    Traceback II
 2930-B                  Traceback II
 3012                    Plastique
 3066                    Traceback
 3066-B                  Traceback
 3066-B2                 Traceback
 3551                    SysLock
 3555                    SysLock
 3880                    Itavir
 4096                    4096
 4096-B                  4096
 4096-C                  4096
 4711                    Perfume
 4870 Overwriting        4870 Overwriting
 5120                    5120
 8920                    Print Screen
 909090h Virus           Burger
 9800:0000 Virus         1554
 A-204                   Jerusalem B
 Advent                  Syslock
 AIDS                    AIDS
 AIDS II                 AIDS II
 AirCop                  AirCop
 AirCop-B                AirCop
 Akuku                   Akuku
 Alabama                 Alabama
 Alameda                 Alameda
 Ambulance               Ambulance Car
 Ambulance Car           Ambulance Car
 Amoeba Virus            1392
 Amstrad                 Amstrad
 Anarkia                 Jerusalem B
 Anarkia-B               Jerusalem B
 Anthrax                 Anthrax
 AntiCad                 1253
 Anti-Pascal             Anti-Pascal
 Anti-Pascal 400         Anti-Pascal II
 Anti-Pascal 440         Anti-Pascal II
 Anti-Pascal 480         Anti-Pascal II
 Anti-Pascal 529         Anti-Pascal
 Anti-Pascal 605         Anti-Pascal
 Anti-Pascal II          Anti-Pascal II
 AntiChrist              AntiChrist
 AP-400                  Anti-Pascal II
 AP-440                  Anti-Pascal II
 AP-480                  Anti-Pascal II
 AP-529                  Anti-Pascal
 AP-605                  Anti-Pascal
 April 1st               Suriv 1.01
 April 1st-B             Suriv 2.01
 Arab                    834 Virus
 Arab Star               Jerusalem B
 Arf                     Arf
 Arf-B                   Arf
 Armagedon               Armagedon
 Armagedon The First     Armagedon
 Armagedon The Greek     Armagedon
 Ashar                   Ashar
 Attention!              Attention!
 Australian 403          Australian 403
 Austrian                Vienna
 Azusa                   Azusa
 Azusa 2                 Azusa
 Basic Virus             5120
 Best Wish               Best Wishes
 Best Wishes             Best Wishes
 Best Wishes B           Best Wishes
 Black Avenger           Dark Avenger
 Black Friday            Jerusalem
 Black Monday            Black Monday
 Blackjack               Cascade-B
 Blood                   Blood
 Blood 2                 Blood
 Bloody!                 Bloody!
 Boot                    Ping Pong-B
 Bouncing Ball           Ping Pong
 Bouncing Dot            Ping Pong
 Brain                   Brain
 Brain Slayer            Slayer Family
 Burger                  Burger
 C-605                   Anti-Pascal
 Captain Trips           Jerusalem B
 Carioca                 Carioca
 Cascade                 Cascade
 Cascade-B               Cascade-B
 Casino                  Casino
 Casper                  Casper
 Century Virus           4096
 Chaos                   Chaos
 Choinka                 Father Christmas
 Christmas In Japan      Christmas In Japan
 Christmas Violator      Violator B4
 Christmas Virus         Christmas Virus
 CIA                     Burger
 Columbus Day            Datacrime, Datacrime II, Datacrime IIB, Datacrime-B
 COM Virus               Friday The 13th COM Virus
 Computer Ogre           Disk Killer
 Cookie                  Cookie
 Cracker Jack            Enigma
 Crash                   Crash
 Crew-2480               Crew-2480
 Cunning                 Cascade
 Cursy                   Cursy
 Dark Avenger            Dark Avenger
 Dark Avenger-B          Dark Avenger
 Dark Avenger II         V2000
 Dark Avenger III        V1024
 Datacrime               Datacrime
 Datacrime II            Datacrime II
 Datacrime IIB           Datacrime IIB
 Datacrime-B             Datacrime-B
 DataLock                DataLock
 DataLock 1.00           DataLock
 DBase                   DBase
 DBF Virus               DBase
 Dead Kennedy            Kennedy
 Death To Pascal         Wisconsin
 December 24th           Icelandic-III
 Deicide                 Deicide
 Den Zuk                 Den Zuk
 Destructor              Destructor V4.00
 Destructor V4.00        Destructor V4.00
 Devil's Dance           Devil's Dance
 Diamond                 V1024
 Diamond-B               V1024
 Diana                   Dark Avenger
 Die Young Virus         V2000
 Dir Virus               Dir Virus
 Discom                  Discom
 Disk Crunching Virus    Icelandic, Saratoga
 Disk Killer             Disk Killer
 Disk Ogre               Disk Killer
 Do-Nothing Virus        Do-Nothing Virus
 Doom II-B               Doom II-B
 Donald Duck             Stoned
 DOS-62                  Vienna
 DOS-68                  Vienna
 Durban                  Saturday The 14TH
 Dutch 555               Dutch 555
 Dyslexia                Solano 2000
 Dyslexia 2.00           Solano 2000
 Dyslexia 2.01           Solano 2000
 EB 21                   Print Screen
 Eddie                   Dark Avenger
 Eddie Virus             Dark Avenger
 Eddie 3                 V651
 EDV                     EDV
 Eight Tunes             Eight Tunes
 Empire                  Evil Empire-B
 Enigma                  Enigma
 European Fish Viruses   Fish Virus
 Evil                    Evil
 Evil Empire             Evil Empire
 Evil Empire-A           Evil Empire
 Evil Empire-B           Evil Empire-B
 Evil-B                  Evil
 F-Word Virus            F-Word Virus
 Fall                    Cascade
 Falling Letters         Cascade, Ping Pong-B
 Falling Letters Boot    Swap Boot
 Father Christmas        Father Christmas
 Fellowship              Fellowship
 FichV                   903
 Fish 6                  Fish Virus
 Fish Virus              Fish Virus
 Five O'Clock Virus      Yankee Doodle
 Flash                   Flash
 Flip                    Flip
 Flip B                  Flip
 Form                    FORM-Virus
 Form Boot               FORM-Virus
 FORM-Virus              FORM-Virus
 Frere Virus             Frere Jacques
 Frere Jacques           Frere Jacques
 Friday 13th             Jerusalem
 Friday 13th COM Virus   Friday The 13th COM Virus
 Friday 13th-B           Friday The 13th COM Virus
 Friday 13th-C           Friday The 13th COM Virus
 FroDo                   4096
 Frog                    Frog's Alley
 Frog's Alley            Frog's Alley
 Fu Manchu               Fu Manchu
 Fuck You                F-Word
 Fumble                  Typo COM
 G-Virus V1.3            Sorry
 Ghost Boot              Ghostballs
 Ghost COM               Ghostballs
 Ghostballs              Ghostballs
 Glenn                   Deicide
 Golden Gate             Golden Gate
 Greemlin                Gremlin
 Green Left Virus        Groen Links
 Green Peace             Green Peace
 Gremlin                 Gremlin
 Grither                 Grither
 Groen Links             Groen Links
 Guppy                   Guppy
 Guppy-B                 Guppy
 Hahaha                  AIDS
 Halloechen              Halloechen
 Hammelburg              405
 Happy Birthday Joshi    Joshi
 Happy N.Y.              Happy New Year, Happy New Year B
 Happy New Year          Happy New Year
 Happy New Year          Happy New Year B
 Hawaii                  Stoned
 Hebrew University       Jerusalem B
 Hemp Virus              Stoned
 HIV                     HIV
 HM2                     Plastique
 Holland Girl            Holland Girl
 Holland Girl 2          Holland Girl 2
 Holo                    Holocaust
 Holocaust               Holocaust
 Hong Kong               Azusa
 Horse                   Naughty Hacker Family
 Horse 2                 Naughty Hacker Family
 Hybrid                  Hybryd
 Hybryd                  Hybryd
 Hymn                    Hymn
 Hymn-2                  Sverdlov
 Icelandic               Icelandic
 Icelandic-II            Icelandic-II
 Icelandic-III           Icelandic-III
 Ick                     IKV 528
 IDF Virus               4096
 IKV 528                 IKV 528
 Internal                1381 Virus
 Invader                 Invader
 Iraqui                  Iraqui Warrior
 Iraqui Warrior          Iraqui Warrior
 Israeli                 Jerusalem, Suriv 1.01, Suriv 2.01, Suriv 3.00
 Israeli Boot            Swap
 Italian                 Ping Pong
 Italian 803             Italian 803
 Italian 803-B           Italian 803
 Italian File            Italian 803
 Italian-A               Ping Pong, Ping Pong B
 Itavir                  Itavir
 Japanese Christmas      Christmas In Japan
 Jeff                    Jeff
 Jerk                    Jerk
 Jerusalem               Jerusalem
 Jerusalem A             Jerusalem
 Jerusalem B             Jerusalem B
 Jerusalem C             Jerusalem B
 Jerusalem D             Jerusalem B
 Jerusalem DC            Jerusalem B
 Jerusalem E             Jerusalem B
 Jerusalem E2            Jerusalem B
 Jocker                  Joker
 JoJo                    JoJo
 JoJo 2                  JoJo 2
 Joker                   Joker
 Joker 2                 Joker 2
 Joker-01                Joker 2
 Joshi                   Joshi
 July 13TH               July 13TH
 June 16TH               June 16TH
 Kamasya                 Kamasya
 Kamikazi                Kamikazi
 Kemerovo                Kemerovo
 Kemerovo                Kemerovo-B
 Kennedy                 Kennedy
 Kennedy-163             Tiny Virus
 Kennedy-333             Kennedy
 Keypress                Keypress
 Korea                   Korea
 Kukac                   Turbo Kukac
 Lazy                    Lazy
 LBC Boot                Korea
 Leapfrog                USSR 516
 Lehigh                  Lehigh
 Lehigh University       Lehigh
 Lehigh-2                Lehigh
 Lehigh-B                Lehigh
 Leprosy                 Leprosy
 Leprosy 1.00            Leprosy
 Leprosy-B               Leprosy
 Liberty                 Liberty
 Liberty-B               Liberty
 Liberty-C               Liberty
 Lisbon                  Lisbon
 Lisbon-B                Lisbon
 Lisbon-B2               Lisbon
 Little Pieces           Little Pieces
 Live after Death Virus  V800
 Lozinsky                Lozinsky
 M.I.R.                  M.I.R.
 Mardi Bros              Mardi Bros
 Marijuana               Stoned
 Mazatlan                Golden Gate
 Merritt                 Alameda
 Mendoza                 Jerusalem B
 Mexican                 Devil's Dance
 MG                      MG
 MG-2                    MG-2
 MG-3                    MG-2
 MGTU                    MGTU
 Miami                   Friday The 13th
 Microbes                Microbes
 Migram                  Migram
 Mini-45                 Mini-45
 Minnow                  ZeroHunt
 MIR                     M.I.R.
 Mirror                  Mirror
 Mistake                 Typo Boot
 MIX1                    MIX1
 MIX2                    MIX2
 MIX/1                   MIX1
 Mix1                    MIX1
 Mix2                    MIX2
 Monxla                  Monxla
 Monxla B                Monxla B
 Mother Fish             Whale
 Munich                  Friday The 13th COM Virus
 Murphy                  Murphy, AntiChrist, HIV, Kamaysa, Migram
 Murphy-1                Murphy
 Murphy-2                Murphy
 Music Boot              MusicBug
 Music Bug               MusicBug
 Music Virus             Oropax
 MusicBug                MusicBug
 Musician                Oropax
 Naughty Hacker          Naughty Hacker Family
 Naughty Hacker Family   Naughty Hacker Family
 Naughty Hacker-A        Naughty Hacker Family
 Naughty Hacker-B        Naughty Hacker Family
 New Jerusalem           New Jerusalem
 New Zealand             Stoned
 News Flash              Leprosy
 Nina                    Nina
 Nomenclature            Nomenklatura
 Nomenklatura            Nomenklatura
 Number 1                Number One
 Number of the Beast     512 Virus
 Number One              Number One
 Ogre                    Disk Killer
 Ohio                    Ohio
 One In Eight            Vienna
 One In Ten              Icelandic, Icelandic-II
 One In Two              Saratoga
 Ontario                 Ontario
 Oropax                  Oropax
 Oulu                    1008
 P1                      Evil, Phoenix, PhoenixD, Proud
 Pakistani               Brain
 Pakistani Brain         Brain
 Palette                 Zero Bug
 Paris                   Paris
 Parity                  Parity
 Park ESS                Jerusalem B
 Payday                  Payday
 Peking                  Alameda
 Pentagon                Pentagon
 Perfume                 Perfume
 Phantom                 Phantom
 Phoenix                 Phoenix
 PhoenixD                PhoenixD
 Ping Pong               Ping Pong
 Ping Pong-B             Ping Pong-B
 Ping Pong-C             Ping Pong-C
 Pixel                   Amstrad
 Pixel 2                 Amstrad
 Plastique               Plastique
 Plastique 1             Plastique
 Plastique 2             Plastique-B
 Plastique 4.51          Plastique
 Plastique 5.21          Plastique-B
 Plastique Boot          Invader
 Plastique-B             Plastique-B
 PLO                     Jerusalem
 Point Killer            Dot Killer
 Polimer                 Polimer
 Polimer Tapeworm        Polimer
 Polish 217              Polish 217
 Polish 217 B            Polish 217
 Polish 529              Polish 529
 Polish 583              Polish 583
 Polish 961              Stone`90
 Polish Stupid           Polish 217
 Polish-2                Turbo 448, Turbo Kukac
 Pray                    ZK900
 Pretoria                June 16TH
 Print Screen            Print Screen
 Print Screen-2          Print Screen
 Proud                   Proud
 PRTSC Virus             Print Screen
 Prudents Virus          1210
 PS-Stoned               Stoned
 PSQR Virus              1720
 Puerto                  Jerusalem B
 Rabid Avenger           Dark Avenger
 RaubKopie               RaubKopie
 Red Diavolyata          Red Diavolyata
 RedX                    Ambulance Car
 Rigor Mortis            Arf
 Rostov                  Stoned
 RPVS                    RPVS
 RPVS-B                  RPVS
 Russian                 Jerusalem
 S-847                   Amstrad
 Sadam                   Saddam
 Saddam                  Saddam
 San Diego               Stoned
 Saturday The 14th       Saturday The 14th
 Saratoga                Saratoga
 Saratoga 2              Icelandic
 Scott's Valley          Scott's Valley
 Seoul                   Alameda
 Sentinel                Sentinel
 Sex Revolution v1.1     Stoned
 Sex Revolution v2.0     Stoned
 SF Virus                SF Virus
 Shake Virus             Shake Virus
 Shoe_Virus              Ashar
 Shoe_Virus-B            Ashar-B
 Skism-1                 Jerusalem B
 Slayer                  Slayer Family
 Slayer Family           Slayer Family
 Slayer-A                Slayer Family
 Slayer-B                Slayer Family
 Slayer-C                Slayer Family
 Slayer-D                Slayer Family
 Slayer-E                Slayer Family
 Slow                    Slow
 Slow-2131               Scott's Valley
 Slowdown                Slow
 Smack                   Smack
 Smithsonian             Stoned
 Solano                  Solano 2000
 Solano 2000             Solano 2000
 Solomon                 1605
 Sorry                   Sorry
 South African           Friday The 13th COM Virus
 Sparse                  Sparse
 Spyer                   Spyer
 Staf                    Staf
 Staff                   Staf
 StarDot                 StarDot 600, StarDot 801
 StarDot 600             StarDot 600
 StarDot 801             StarDot 801
 Stealth Viruses         EDV, Fish, Holocaust, Joshi, Murphy, V651, V800, V1024,
                         V2000, V2100, ZeroHunt, 512, 4096, Tequila,
                         Naughty Hacker Family
 Stone`90                Stone`90
 Stone-90                Stone`90
 Stoned                  Stoned
 Stoned II               Stoned
 Stoned-B                Stoned
 Stoned-C                Stoned
 Stoned-D                Stoned
 Stoned-E                Stoned
 Stoned-F                Stoned
 Striker #1              Striker #1
 Stupid Virus            Do-Nothing
 Subliminal              Subliminal 1.10
 Subliminal 1.10         Subliminal 1.10
 Sunday                  Sunday
 Sunday-B                Sunday
 Sunday-C                Sunday
 Suomi                   1008
 SuperHacker             Jerk
 Suriv 1.01              Suriv 1.01
 Suriv 2.01              Suriv 2.01
 Suriv 3.00              Suriv 3.00
 Suriv A                 Suriv 1.01, Suriv 2.01
 Suriv B                 Suriv 3.00
 Suriv01                 Suriv 1.01
 Suriv02                 Suriv 2.01
 Suriv03                 Suriv 3.00
 SVC V4.00               USSR 1689
 Sverdlov                Sverdlov
 Sverdlov-B              Sverdlov
 SVir                    SVir
 SVir_0                  SVir
 SVir-A                  SVir
 SVir-B                  SVir
 Swami                   Murphy
 Swap                    Swap
 Swedish Disaster        Swedish Disaster
 Swiss 143               Swiss 143
 Swiss 1813              Jerusalem B
 Sylvia                  Holland Girl
 Sylvia 2                Holland Girl 2
 SysLock                 Syslock
 System Virus            Icelandic-II
 Taiwan                  Taiwan
 Taiwan 2                Taiwan
 Taiwan 3                Taiwan 3
 Taiwan 4                Taiwan 4
 Taiwan-B                Taiwan
 Talentless Jerk         Jerk
 Tannenbaum              Christmas Virus
 Taunt                   AIDS
 Tel Aviv                1605
 Ten Bytes               1554
 Tequila                 Tequila
 Tester                  Tester
 TestVir                 Tester
 The Plague              The Plague
 Thor                    Arf
 Time                    Monxla
 Time B                  Monxla B
 Tiny Family             Tiny Family
 Tiny Virus              Tiny Virus
 Tiny 134 Virus          Tiny Family
 Tiny 138 Virus          Tiny Family
 Tiny 143 Virus          Tiny Family
 Tiny 154 Virus          Tiny Family
 Tiny 156 Virus          Tiny Family
 Tiny 158 Virus          Tiny Family
 Tiny 159 Virus          Tiny Family
 Tiny 160 Virus          Tiny Family
 Tiny 163 Virus          Tiny Virus
 Tiny 169 Virus          Tiny Family
 Tiny 198 Virus          Tiny Family
 Toothless Virus         W13
 TP04VIR Virus           Vacsina
 TP05VIR Virus           Vacsina
 TP06VIR Virus           Vacsina
 TP16VIR Virus           Vacsina
 TP23VIR Virus           Vacsina
 TP24VIR Virus           Vacsina
 TP25VIR Virus           Vacsina
 TP33VIR Virus           Yankee Doodle
 TP34VIR Virus           Yankee Doodle
 TP38VIR Virus           Yankee Doodle
 TP41VIR Virus           Yankee Doodle
 TP42VIR Virus           Yankee Doodle
 TP44VIR Virus           Yankee Doodle
 TP45VIR Virus           Yankee Doodle
 TP46VIR Virus           Yankee Doodle
 Traceback               Traceback
 Traceback II            Traceback II
 Traceback II-B          Traceback II
 Traceback-B             Traceback
 Traceback-B2            Traceback
 Travel Virus            V2000
 Turbo @                 Turbo 448
 Turbo 448               Turbo 448
 Turbo Kukac             Turbo Kukac
 Turbo Kukac 9.9         Turbo Kukac
 Typo Boot               Typo Boot
 Typo COM                Typo COM
 UIUC Virus              Ashar
 UIUC Virus-B            Ashar
 Unesco                  Vienna
 UScan Virus             V2100
 USSR                    USSR
 USSR 257                Kemerovo
 USSR 311                USSR 311
 USSR 394                Attention!
 USSR 492                USSR 492
 USSR 516                USSR 516
 USSR 600                USSR 600
 USSR 707                USSR 707
 USSR 711                USSR 711
 USSR 830                Red Diavolyata
 USSR 948                USSR 948
 USSR 1049               USSR 1049
 USSR 1689               USSR 1689
 USSR 2144               USSR 2144
 V-1                     1253
 V-277                   Amstrad
 V-299                   Amstrad
 V-311                   USSR 311
 V-345                   Amstrad
 V-847                   Amstrad
 V-847B                  Amstrad
 V-852                   Amstrad
 V-Alert                 1554
 V605                    Anti-Pascal
 V651                    V651
 V791                    V801
 V800                    V800
 V800M                   V800
 V801                    V801
 V920                    DataLock
 V1024                   V1024
 V1226                   1226
 V1226D                  1226D
 V1226M                  1226D
 V1277                   Murphy
 V1302                   Proud
 V1521                   Murphy
 V1600                   Happy New Year
 V1701New                Evil
 V1701New-B              Evil
 V2000                   V2000
 V2000-B                 V2000
 V2100                   V2100
 V2P1                    1260
 V2P2                    V2P2
 V2P6                    V2P6
 V2P6-B                  V2P6
 V2P6Z                   V2P6Z
 Vacsina                 Vacsina
 VBasic Virus            5120
 Vcomm                   Vcomm
 Vera Cruz               Ping Pong
 VFSI                    VFSI
 VGA2CGA                 AIDS
 VHP                     VHP
 VHP2                    VHP2
 VHP-348                 VHP
 VHP-353                 VHP
 VHP-367                 VHP
 VHP-435                 VHP
 VHP-623                 VHP2
 VHP-627                 VHP2
 Victor                  Victor
 Vien6                   Vienna
 Vienna                  Vienna
 Vienna 535              Monxla B
 Vienna 637              VComm
 Vienna 646              646
 Vienna C                646
 Vienna-B                Vienna
 Vienna-B 645            Vienna
 Violator                Violator
 Violator BT             Violator
 Violator B1             Violator
 Violator B2             Violator
 Violator B3             Violator
 Violator B4             Violator B4
 Violator B4-1           Violator B4
 Violator B4-B           Violator B4
 Violator Strain B       Violator
 Violator Strain B4      Violator B4
 VirDem                  VirDem
 VirDem 2                VirDem
 Virus-90                Virus-90
 Virus-B                 Friday The 13th COM Virus
 Virus101                Virus101
 Voronezh                Voronezh
 Voronezh B              Voronezh
 VP                      VP
 Vriest                  Vriest
 W13                     W13
 W13-A                   W13
 W13-B                   W13
 Westwood                Westwood
 Whale                   Whale
 Wisconsin               Wisconsin
 Wolfman                 Wolfman
 Wolfman 2               Wolfman
 XA1                     Christmas Tree
 Xmas In Japan           Christmas In Japan
 Yale                    Alameda
 Yankee 2                Yankee 2
 Yankee Doodle           Yankee Doodle
 Yankee Doodle Dropper   Slayer Family
 Yankee Virus            Yankee 2
 Yankee-go-Home          Yankee 2
 Yap                     Yap
 Yukon Overwriting       Yukon Overwriting
 Z The Whale             Whale
 Zero Bug                Zero Bug
 ZeroHunt                ZeroHunt
 ZeroHunt B              ZeroHunt
 ZK900                   ZK900
-------------------------------------------------------------------------------
                      Virus Information Summary List
                         Virus Relationship Chart

512 Virus       --> 512-B       --> 512-C       --> 512-D
                --> 512-E
                --> 512-F

834             --> 834-B/Arab

1226            --> 1226M       --> 1226D

4096            --> 4096-B      --> 4096-C
                --> Fish        --> Whale

AirCop          --> AirCop-B

Alameda         --> Alameda-2
                --> Golden Gate --> Golden Gate-B --> Golden Gate-C
                --> SF Virus

Anti-Pascal     --> AP-529      --> AP-400      --> AP-440      --> AP-480

        Note: AP-480, AP-440, and AP-400 are grouped together in the listing
              as Anti-Pascal II

Azusa           --> Azusa 2

Blood           --> Blood2

Brain           --> Ashar
                --> Clone
                --> Chaos
                --> EDV

Cascade/1701    --> 1701-B
                --> 1704        --> 1704 Format
                                --> 1704-B
                                --> 17Y4
                                --> Cunning

Datacrime       --> Datacrime-B
                --> Datacrime II --> Datacrime IIB

Do-Nothing      --> Saddam

Flip            --> Flip-B      --> Tequila

Fri 13th COM    --> Fri 13th-B  --> Fri 13th-C
                --> Virus-B

Happy New Year  --> Happy New Year B

HM2           --:               --> Plastique COBOL
                --> Plastique   --> Plastique 4.21      --> Plastique 5.21
Jerusalem B   --:                                                :
                                                                 V
                                                            Invader

Holland Girl    --> Holland Girl 2

Icelandic       --> Saratoga
                --> Iceland II  --> Icelandic III
                                --> Dec 24th
                --> Mix1        --> Mix1-B
                                --> Mix2

JoJo            --> JoJo 2

Kemerovo        --> Kemerovo-B

Kennedy         --> Tiny 163

Leprosy         --> Leprosy-B   --> The Plague

MG              --> MG-2        --> MG-3

Murphy-1        --> Murphy-2
                --> AntiChrist
                --> HIV
                --> Kamasya
                --> Migram      --> Smack
                --> Swami

Naughty Hacker-B --> Naughty Hacker-A
                 --> Horse              --> Horse 2

Ohio            --> Den Zuk

Perfume         --> Sorry

Phoenix         --> PhoenixD
                --> Evil-B      --> Evil

Ping Pong       --> Ping Pong-B  --> Ping Pong-C
                --> Big Italian
                --> Typo
                --> Print Screen --> Print Screen-2
                --> Ghostballs

Pixel           --> Amstrad     --> V-847B
                                --> V-852
                --> V-345       --> V-299       --> V-277
                --> S-847       --> Pixel 2

Polish 217      --> Polish 217 B

Slow            --> Scott's Valley

Stoned          --> Stoned-B    --> Rostov
                                --> Sex Revolution v1.1 --> Sex Revolution v2.0
                                --> Stoned-C
                                --> Stoned-D
                                --> Stoned-E
                                --> Stoned-F
                                --> Stoned II
                                --> Swedish Disaster
                                --> PS-Stoned
                                --> Evil Empire         --> Evil Empire-B

Suriv 3.00      --> Jerusalem   --> Fu Manchu   --> Taiwan 3
                                --> Jerusalem B --> New Jerusalem
                                                --> Payday
                                                --> Sunday      --> Sunday-B
                                                                --> Sunday-C
                                                --> Jerusalem C
                                                --> Jerusalem D
                                                --> Jerusalem E
                                                --> Jerusalem F (Spanish)
                                                --> 1720/PSQR
                                                --> 1210/Prudents
                                                --> Frere Jacques
                                                --> Anarkia     --> Anarkia-B
                                                --> Slow
                                                --> Westwood
                                                --> 1605        --> 1605-B
                                                --> Park ESS
                                                --> Skism-1
                                                --> (also see HM2 above)
                                                --> Discom
                                                --> Captain Trips
                                                --> Swiss 1813

Sverdlov        --> Sverdlov-B

Syslock         --> Macho       --> Macho-B
                --> Advent
                --> Cookie

Tiny-198        --> Tiny-167
                    --> Tiny-160
                        --> Tiny-159
                            --> Tiny-158
                                --> Tiny-156
                                    --> Tiny-154
                                        --> Tiny-143
                                            --> Tiny-138
                                                --> Tiny-134
                                                    --> Tiny-133

        Note: The Tiny-nnn Viruses indicated above are grouped together in
              the listing as "Tiny Family".  The Tiny-163 virus is not
              related to the above group of viruses.

Traceback II    --> Traceback   --> Traceback-B --> Traceback-B2
                --> Traceback II-B

V1024           --> Dark Avenger --> V651
                                 --> V800       --> V800M
                                 --> V2000      --> V2000-B
                                                --> V2100   --> M.I.R.
                                 --> Dark Avenger-B         --> Rabid Avenger
                --> V1024-B      --> Diamond    --> Diamond-B
                                 --> Gremlin

Vienna          --> Father Christmas
                --> Lisbon      --> Lisbon-B    --> Lisbon-B2
                --> Ghostballs
                --> 1260        --> V2P2        --> Casper
                                                --> V2P6        --> V2P6Z
                --> W13/V-534   --> W13-B/V-507
                --> Wien (Poland)
                --> Vien6
                --> Vienna-B    --> Vienna-B 645
                --> Violator    --> Violator BT
                                    --> Violator B1
                                        --> Violator B2
                                            --> Violator B3
                                                --> Violator B4
                                                    --> Violator B4-1
                                                        --> Violator B4-B
                --> Grither
                --> VHP-348     --> VHP-353     --> VHP-367     --> VHP-435
                --> VHP-623     --> VHP-627
                --> Iraqui Warrior
                --> Arf-B       --> Arf

        Note: VHP-348, VHP-353, VHP-367, and VHP-435 are listed as VHP.
              VHP-623 and VHP-627 are listed as VHP2.

Virus-90        --> Virus101

Wolfman         --> Wolfman 2

Yankee 2        --> Enigma

ZeroHunt        --> ZeroHunt B


-------------------------------------------------------------------------------
                        Virus Information Summary List
                               Revision History

15 May, 1991 - VSUM9105.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            646             - Vienna 646 Alias Added
            903             - 903-B Variant Added
            AirCop          - AirCop-B Variant Added
            Ambulance Car   - Ambulance Alias Added
            AntiChrist      - Origin Updated
            Arf             - Arf-B Variant Added
            Azusa           - Hong Kong Alias Added
                            - Azusa 2 Variant Added
            Christmas In Japan
                            - Japanese Christmas Alias Added
            Dark Avenger    - Rabid Avenger Variant Added
            HIV             - Origin Updated
            Kamasya         - Origin Updated
            Kennedy         - Kennedy-333 Alias Added
            Lisbon          - Description Updated
                            - Lisbon-B Variant Added
                            - Lisbon-B2 Variant Added
            Migram          - Origin Updated
            Monxla B        - Vienna 535 Alias Added
            Murphy          - Swami Variant Added
            Saddam          - Sadam Alias Added
            Scott's Valley  - Slow-2131 Alias Added
            Stoned          - PS-Stoned Variant Added
            Tiny Virus      - Kennedy-163 Alias Added
            VComm           - Vienna 637 Alias Added
            Violator        - Violator BT Variant Added
                            - Violator B1 Variant Added
                            - Violator B2 Variant Added
                            - Violator B3 Variant Added
            Violator B4     - Violator B4-1 Variant Added
                            - Violator B4-B Variant Added
      The following new viruses have been added to the listing:
            2560
            Doom II-B
            Evil Empire
            Evil Empire-B
            Green Peace
            Gremlin
            Joker 2
            Mini-45
            M.I.R.
            Naughty Hacker Family
                            - Naughty Hacker-A
                            - Naughty Hacker-B
                            - Horse
                            - Horse 2
            Smack
            Tequila
            Vriest
      Information for the following anti-viral products has been added or
      updated:
            IBM Scan - Updated for Version 2.00.01
            CleanUp  - Updated for Version V77
            ViruScan - Updated for Version V77

20 April, 1991 - VSUM9104.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            405             - Hammelburg Alias Added
            512             - V512-E Variant
                            - V512-F Variant
            834             - Arab Alias Added
                            - 834-B Variant
            1381            - Internal Alias Added
                            - 1381-B Variant
            1605            - Tel Aviv Alias Added
            Amstrad         - Pixel, Pixel 2, and S-847 Aliases Added
                            - Pixel 2 Variant
                            - S-847 Variant
            Enigma          - Reference to Yankee 2
            Friday The 13th COM
                            - Virus B Alias Added
            Guppy           - Guppy-B Variant
            Mix1            - Reference to Mix2
            Murphy          - References to AntiChrist, HIV, Kamasya, Migram
            Ping Pong B     - Italian-A Alias Added
            Sverdlov        - Hymn-2 Alias Added
                            - Sverdlov-B Variant
            SVir            - SVir_0 Variant
            V1024           - Diamond Alias Added
                            - Diamond Variant
                            - Diamond-B Variant
            V2P6            - V2P6-B Variant
            Yankee 2        - Reference to Enigma
      The following new viruses have been added to the listing:
            AntiChrist
            Casino
            Crash/1075
            Frog's Alley
            HIV
            Italian 803     - Italian 803
                            - Italian 803-B
            Kamasya
            Migram
            Mix2
            Raubkopie
            Slayer Family   - Slayer-A
                            - Slayer-B
                            - Slayer-C
                            - Slayer-D
                            - Slayer-E
            Sparse
            Staf
            StarDot 600
            StarDot 801
            Tester/TestVir
            V801/V791
            Yap Virus
            ZK900/Pray
      Information for the following anti-viral products has been added or
      updated:
            NAV      - Norton AntiVirus, Version 1.00
            ViruScan - updated for version V76

17 March, 1991 - VSUM9103.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            1575            - 1575-C Variant
            1605            - 1605-B/Solomon Variant
            Jerusalem B     - Captain Trips Variant
                            - Swiss 1813 Variant
            Kemerovo        - Kemerovo-B Variant
            Vienna          - Description Updated
            Wolfman         - Wolfman 2 Variant
            ZeroHunt        - ZeroHunt B Variant
      The following new viruses have been added to the listing:
            834 Virus
            Arf Virus
            Australian 403
            Azusa
            Crew-2480
            Deicide
            Dutch 555
            Enigma
            Jerk
            Lazy
            Phantom
            Striker #1
      Information for the following anti-viral products has been added or
      updated:
            Clean-Up - updated for version V75
            ViruScan - updated for version V75

14 February, 1991 - VSUM9102.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            4096            - 4096-C Variant
            Aids            - Aids B Variant
            Flip            - Flip B Variant
            Liberty         - Clarificiation to entry, change to Liberty B
                              identification string for use with Scan.
                            - Liberty B Variant
            Paris           - Update to description
            Plastique       - Plastique COBOL Variant
            Polish 217      - Polish 217 B Variant
            Stoned          - rewrote entry & merged in Stoned II entry
                            - Rostov Variant
                            - Sex Revolution v1.1 Variant
                            - Sex Revolution v2.0 Variant
                            - Stoned E Variant
                            - Stoned F Variant
            USSR 1689       - Added SVC V4.00 alias
      The following new viruses have been added to the listing:
            903
            1575            - 1575 Virus
                            - 1575-B Variant
            4870 Overwriting
            Akuku
            Cookie
            Destructor V4.00
            Dir Virus
            Discom
            Grither
            Happy New Year    - Happy New Year
                              - Happy New Year B Variant
            Holland Girl 2
            Hybryd
            IKV 528
            Iraqui Warrior
            JoJo 2
            Little Pieces/1374
            MG
            MG-2              - MG-2
                              - MG-3 Variant
            Monxla B
            Nina
            Parity
            Saddam
            Sentinel
            Swedish Disaster
            Swiss 143
            The Plague
            USSR 311
            USSR 492
            Violator B4
            Yukon Overwriting
      Information for the following anti-viral products has been added
      or updated:
            Pro-Scan  - additional disinfection updates for version 2.01
            Clean-Up  - updated for version V74
            ViruScan  - updated for version V74

08 January, 1991 - VSUM9101.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            4096         - additional information added
            Flip         - additional information added
            Invader      - correction to Type Code
            Jerusalem B  - Skism-1 Variant
            Nomenklatura - additional damage information added
            Plastique    - additional information, activation data
            Plastique B  - additional information, activation data
            Tiny Family  - Tiny 133 Variant
      The following new viruses have been added to the listing:
            Attention!
            Best Wishes - Best Wishes
                        - Best Wishes B
            Bloody!
            F-Word Virus
            Holocaust
            Hymn
            Jeff
            Kemerovo
            Lozinsky
            MGTU
            MusicBug
            Polish 583
            Red Diavolyata
            Stone`90/Polish 961
            Sverdlov
            USSR 516
            USSR 600
            USSR 707
            USSR 711
            USSR 948
            USSR 1049
            USSR 1689
            USSR 2144
            Voronezh    - Voronezh
                        - Voronezh B
            ZeroHunt
      Information for the following anti-viral products has been added or
      updated:
            Clean-Up - updated for version V72
            Pro-Scan - updated for version 2.01
            ViruScan - updated for version V72

03 December, 1990 - VSUM9013.ZIP (Not publicly distributed.)
      Pro-Scan Version 2.0 has not been added to the listing.

02 December, 1990 - VSUM9012.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            Burger      - 505 Variant
                        - 509 Variant
                        - 541 Variant
                        - CIA Variant
            Christmas   - Tannenbaum alias added
            Kennedy     - 333 alias added
            Leprosy     - News Flash alias added
            Liberty     - Liberty-B Variant
            Slow        - Updated for file length increases,
                          Slowdown alias added
            Wisconsin   - Updated for file date/time change
            VirDem      - VirDem 2 Variant
            Virus-90    - Added description submitted by P. Toulme
            Virus101    - Added description submitted by P. Toulme
            Yankee 2    - Yankee-go-Home alias added
                        - 1624 variant added
      The following new viruses have been added to the listing:
            646
            Carioca
            DataLock
            Dot Killer
            Father Christmas
            Groen Links
            Keypress
            Mirror
            Monxla
            Polimer
            Polish 217
            Polish 529
            Spyer
            Taiwan 4/2576
            Turbo 448
            Turbo Kukac
            USSR
      Information for the following anti-viral products/programs have been
      added/updated with this release:
            Clean-Up    - McAfee Associates' Clean-Up Disinfector, Vers V71
            Pro-Scan    - McAfee Associates' Pro-Scan Anti-Viral, Vers. 2.0
            VirHunt     - Digital Dispatch, Inc.'s VirHunt Anti-Viral, Vers 2.0
                          Note: boot sector disinfection not tested
            ViruScan    - McAfee Associates' ViruScan Detector, Vers V71
      Removed the following anti-viral products for the reason indicated:
            M-1704      - replaced by McAfee Associates' Clean-Up
            M-1704C     - replaced by McAfee Associates' Clean-Up
            M-DAV       - replaced by McAfee Associates' Clean-Up
            M-JRUSLM    - replaced by McAfee Associates' Clean-Up
            M-Vienna    - replaced by McAfee Associates' Clean-Up

02 November, 1990 - VSUM9011.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            Amstrad     - V852 Variant
            Anthrax     - Updated information
            Jerusalem B - Park ESS Variant
            Tiny Family - Tiny 134 Variant
                        - Tiny 138 Variant
                        - Tiny 143 Variant
                        - Tiny 154 Variant
                        - Tiny 156 Variant
            V2100       - Updated information
      The following new viruses have been added to the listing:
            Guppy
            Proud/V1302
            VFSI

05 October, 1990 - VSUM9010.ZIP
      [Note: There was no VSUM9009 release.]
      The following virus descriptions have been updated, or new variants
      added:
            512         - Clarification of why file damage may occur
            1008        - Origin information, Suomi alias
            4096        - FroDo alias
            Anti-Pascal - correction to indicated text string
            Cascade     - 17Y4 Variant
            Dark Avenger- Dark Avenger-B Variant
            EDV         - Added Cursy alias and activation information
            Evil        - previously in VSUM9008 as V1701New and V1701New-B
            Flash       - Symptom and activation information
            FORM-Virus  - Activation information
            Jerusalem B - Jerusalem DC Variant
            Leprosy     - Leprosy-B Variant
            Paris       - rename of virus listed as TCC in VSUM9008
            Syslock     - Advent Variant
            Taiwan      - Taiwan-B Variant
            Tiny Virus  - Origin information
      The following new viruses have been added to the listing:
            1605
            Black Monday
            Blood       - Blood Variant
                        - Blood2 Variant
            Burger
            Casper
            Christmas In Japan
            Invader
            Kamikazi
            Nomenklatura
            Number One
            Scott's Valley
            Stoned II
            SVir        - SVir-A Variant
                        - SVir-B Variant
            Westwood
            Whale
            V2P2
            V2P6
            V2P6Z
            Violator
            Wisconsin
      The following entries in the cross-reference have been corrected:
            1226D       - incorrectly pointed to V1226D instead of 1226D
            1226M       - incorrectly pointed to V1226D instead of 1226D
            Brain       - missing from VSUM9008 cross-reference
      Information for the following anti-viral products/programs have been
      added/updated with this release:
            CleanUp     - McAfee Associates' CleanUp Disinfector, Version V67
            AVTK        - Dr. Solomon's Anti-Viral Toolkit, Version 3.5
            F-Prot      - Fridrik Skulason's F-Prot, Version 1.12
            VirexPC     - MicroCom's Virex PC, Version 1.10B
            ViruScan    - McAfee Associates' ViruScan Detector, Version V67
            [Note: For ViruScan, as of version V67, any viruses which now
            require the /X command line parameter to be used have been
            indicated under Detection Method.]
      The following viruses have not been added to the listing at this time
      for the reason indicated:
            Big Italian - No Sample Available
            TP43Vir     - Sample does not replicate.
            Doom2       - Unable to get samples to replicate.

10 August, 1990 - VSUM9008.ZIP
      The following virus descriptions have been updated, or new variants
      added:
            1720        - Activation information added
            Anti-Pascal - Anti-Pascal 529/AP-529 Variant
            Sunday      - Sunday-B Variant
                        - Sunday-C Variant
            Tiny Virus  - previously in VSUM9007 as 163 COM Virus
            Traceback   - Traceback-B Variant
                        - Traceback-B2 Variant
            Traceback II
                        - Traceback II-B Variant
            V800        - V800M Variant
            Vienna      - Vienna-B 645 Variant
      The following new viruses have been added to the listing:
            382 Recovery Virus
            1226        - 1226 Virus
            1226D       - 1226D Variant
                        - 1226M Variant
            1253/V-1
            AirCop
            Anthrax
            Anti-Pascal II
                        - Anti-Pascal 400/AP-400
                        - Anti-Pascal 440/AP-440
                        - Anti-Pascal 480/AP-480
            Fellowship
            Flip
            Leprosy
            Mardi Bros
            Ontario
            Phoenix/P1
            PhoenixD/P1
            Plastique   - HM2
                        - Plastique
                        - Plastique 4.51
            Plastique-B - Plastique 5.21
            RPVS/453    - RPVS
                        - RPVS-B Variant
            TCC
            Tiny Family - Tiny 158 Virus
                        - Tiny 159 Virus
                        - Tiny 160 Virus
                        - Tiny 167 Virus
                        - Tiny 198 Virus
            V1701New/P1 - V1701New
                        - V1701New-B (earlier version)
            V2100
            Wolfman
      Information on the following anti-viral products was updated or added
      to this release:
            CleanUp  - Version V66
            Pro-Scan - Version 1.4
            VirexPC  - Version 1.1
            ViruScan - Version V66
      The following viruses have not been included in the listing at this
      time, for the reason indicated:
            Advent      - No Sample Available
            Big Italian - No Sample Available
            Stoned II   - No Sample Available

15 July, 1990 - VSUM9007.ZIP
      Added Virus Relationship Chart section to document, as well as new
      data field "V Status" to all entries (see introduction and format
      information for description).
      The following viruses have been updated, or new variants added:
            1554
            Amstrad
            Cascade     - Cunning Variant
            Disk Killer
            Ghostballs  - combined Ghost COM and Ghost Boot
            Jerusalem B - Puerto Variant
            Kennedy
            Lehigh      - Lehigh-B Variant
            Vienna      - VHP-627 Variant
                        - Vien6 Variant
            W13
      The following new viruses were added to the listing:
            1008 Virus
            1381 Virus
            Ambulance Car
            Anti-Pascal Virus
            Armagedon
            Flash
            FORM-Virus
            Joshi
            July 13th
            Microbes
            Print Screen
            Print Screen - Print Screen-2 Variant
            Sorry
            Taiwan 3
            V651/Eddie 3
            V1024/Dark Avenger 3
            VHP         - VHP-348 Variant
                        - VHP-353 Variant
                        - VHP-367 Variant
                        - VHP-435 Variant
            VHP2        - VHP-623 Variant
                        - VHP-627 Variant

15 June, 1990 - VSUM9006.ZIP
      Many viruses had their descriptions updated, the ones listed below
      receiving updates for variants or major changes:
            163 COM Virus
            512         - 512-B Variant
                        - 512-C Variant
                        - 512-D Variant
            1554 Virus
            4096        - 4096-B Variant
            Amstrad     - Pixel/V-345 Variant
                        - V-277 Variant
                        - V-299 Variant
                        - V-847 Variant
                        - V-847B Variant
            Jerusalem B - A-204 Variant
                        - Anarkia Variant
                        - Anarkia-B Variant
                        - Mendoza Variant
            Ping Pong-B - Ping Pong-C Variant
            Solano 2000 - Dyslexia 2.01 Variant
            V2000       - V2000-B/Die Young Variant
            Vacsina     - TP04VIR Variant
                        - TP05VIR Variant
                        - TP06VIR Variant
                        - TP16VIR Variant
                        - TP23VIR Variant
                        - TP24VIR Variant
                        - TP25VIR Variant
            Yankee Doodle
                        - TP33VIR Variant
                        - TP34VIR Variant
                        - TP38VIR Variant
                        - TP41VIR Variant
                        - TP42VIR Variant
                        - TP44VIR Variant
                        - TP45VIR Variant
                        - TP46VIR Variant
            Vienna      - VHP-435
                        - VHP-623
      The Vienna-B variant has been moved under the Vienna entry.
      The following new viruses were added to the listing:
            5120
            Eight Tunes
            Fish Virus
            Frere Jacques
            JoJo
            Liberty
            Murphy       - 2 variants (Murphy-1 and Murphy-2)
            Shake Virus
            Slow
            Subliminal 1.10
            V800
            Victor
            VirDem
            VP
            Yankee 2

4 May, 1990 - VSUM9005.ZIP (Not publicly distributed.)
      Added listings for Discovered, Symptoms, Origin, Subdivided
      memory-resident classes, Aligned data entry blocks, placed files
      in ASCII order, placed revision history in descending order.
      Information on the following virii was updated:
            1168/Datacrime
            1280/Datacrime
            Kennedy

18 April, 1990 - VSUM9004.ZIP
      Information on the following viruses was updated:
            Friday The 13th Original COM Virus
            Halloechen
            Jerusalem
            Jerusalem B
            Stoned
            Sunday
            VComm
            4096
      The 1559 virus has been renamed to the 1554 virus in order to
      accurately reflect the virus's effective length.
      The following new viruses were added to the listing:
            AIDS II
            Anarkia (see Jerusalem B)
            Christmas Virus
            Itavir
            June 16TH
            Kennedy
            Korea
            Saturday The 14th
            Solano 2000
            Spanish Jerusalem B (see Jerusalem B)
            V2000
            1210
            1392
            1720
       McAfee Associates' PRO-SCAN commercial anti-viral program, has
       been added, as well as the information for IBM's VirScan program
       updated to reflect IBM's March 1990 program release.

22 February, 1990 - Not publicly distributed.
      Information on the following viruses was updated:
            Disk Killer
      The following new viruses were added to the listing:
            EDV
            512
            1559

18 February, 1990 - VSUM9003.ZIP
     Change to Copyright notice to reflect author's full name.
     Information on the following viruses has been updated:
            Taiwan
            4096

04 February, 1990 - VSUM9002.ZIP
     Second release of listing, which now includes updated information
     for the following viruses:
            Alabama
            Chaos
            Den Zuk
            Datacrime II, Datacrime IIB
            Do-Nothing
            Icelandic, Icelandic-II
            Ohio
            Saratoga
            Stoned
            Swap
            SysLock
            Traceback, Traceback II (was 2930 in previous release)
            Typo Boot
     The following new Ms-Dos computer viruses were added to the
     listing:
            Halloechen
            Icelandic-III
            Joker
            Perfume
            Vcomm
            Virus101
            W13
            1260

15 January, 1990 - VSUM9001.ZIP
     First release of listing, which contained 52 of 61 known Ms-Dos
     computer viruses.  Of the 9 known viruses which were not
     completed, they contained very basic information, though no
     detailed description, those viruses were:
            Chaos                Swap
            Icelandic            Taiwan
            Icelandic-II         Typo Boot
            Ohio                 2930
            Saratoga



 been added to the listing:
            Attention!
            Best Wishes - Best Wishes
                        - Best Wishes B
            Bloody!
            F-Word Virus
            Holocaust
            Hymn
            Jeff
            Kemerovo
            Lozinsky
            MGTU
            MusicBug
            Polish 583
            Red Diavolyata
            Stone`90/Polish wire connected to it. Your finished product should look something
like this:

                   --/-/--
                  :S P S T:
                   -------
                   ::   ::
  -----GREEN WIRE--::   ::----<RR>
                               !
                            10K OHM
                               !
                               !
     -----WHITE WIRE-----------\\
------BLUE WIRE-----------------<FF>

This is simply the basic wiring, if you decide to become one with a