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OS2SCAN FOR OS/2 Version 9.0V99
Copyright (C) 1989 - 1992 by McAfee Associates
All rights reserved.
Documentation by Aryeh Goretsky.
McAfee Associates (408) 988-3832 office
3350 Scott Blvd, Bldg. 14 (408) 970-9727 fax
Santa Clara, CA 95054 (408) 988-4004 BBS (25 lines)
U.S.A. USR HST/v.32/v.42bis/MNP1-5
CompuServe GO MCAFEE
InterNet support@mcafee.COM
TABLE OF CONTENTS:
WHAT'S NEW . . . . . . . . . . . . . . . . . . . . . . . . . .2
- New features added in this release
- System Requirements
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . .3
- Detection of known viruses
- Detection of new and unknown viruses
SYNOPSIS . . . . . . . . . . . . . . . . . . . . . . . . . . .4
- Technical description of known virus detection
- Technical description of new/unknown virus detection
AUTHENTICITY . . . . . . . . . . . . . . . . . . . . . . . . .5
- How to verify the OS2SCAN.EXE program file
COMMAND SUMMARY. . . . . . . . . . . . . . . . . . . . . . . .6
- One-line description of switches
OPTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . .8
- Detailed explanation of switches
EXAMPLES . . . . . . . . . . . . . . . . . . . . . . . . . . .13
- Samples of frequently-used options
VIRUS REMOVAL. . . . . . . . . . . . . . . . . . . . . . . . .14
- How to manually remove a virus
REGISTRATION . . . . . . . . . . . . . . . . . . . . . . . . .15
- How to register OS2SCAN
TECHNICAL SUPPORT INFORMATION . . . . . . . . . . . . . . . .16
- Information you should have ready when calling
OBTAINING THE LATEST VERSION OF OS2SCAN. . . . . . . . . . . .17
- BBS, CompuServe, and Internet access to OS2SCAN
APPENDIX A . . . . . . . . . . . . . . . . . . . . . . . . . .18
- Creating a virus string file with the /EXT option
Page 1
OS2SCAN FOR OS/2 Version 9.0V99 Page 2
WHAT'S NEW
Version 99 is the first release of SCAN for OS/2 (OS2SCAN).
Like it's DOS-based counterpart, VIRUSCAN (for DOS), OS2SCAN
searches PC's for computer viruses in memory, the master boot
record (partition table), boot sector, and files. However,
OS2SCAN contains several important differences:
■ Since OS/2 operates in a protected mode environment it can
only check its own area of memory or "memory image" for
viruses. Viruses in a DOS session or VDM will not be
detected in memory by OS2SCAN.
■ OS2SCAN does not have the /CHKHI, /M, /MAINT, /NOMEM,
or /UNATTEND switches that VIRUSCAN does.
■ The /SAVE switch does not modify the OS2SCAN.EXE file.
Instead, it creates a SCAN.INI file.
■ OS2SCAN does not return an ERRORLEVEL for DOS batch files.
Version 99 detects 865 viruses, or counting variants,
1,561. For a complete list of known viruses, refer to the
enclosed VIRLIST.TXT file. For a description of known viruses
please refer to Patricia Hoffman's Hypertext VSUM.
SYSTEM REQUIREMENTS
OS2SCAN requires IBM OS/2 Version 2.00(GA) or above.
OS2SCAN is designed to check stand-alone and networked PC's
for viruses. For network file servers please use NETSCAN for
DOS instead.
OS2SCAN displays messages in English, French, or Spanish
(/FR and /SP switches).
NOTE: WRITE-PROTECT THE FLOPPY DISK CONTAINING THE OS2SCAN FOR
OS/2 (OS2SCAN.EXE) PROGRAM BEFORE SCANNING TO PREVENT IT
FROM BECOMING INFECTED BY A COMPUTER VIRUS.
OS2SCAN FOR OS/2 Version 9.0V99 Page 3
OVERVIEW (Known Virus Detection)
OS2SCAN FOR OS/2 Version 9.0V99 (filename OS2SCAN.EXE)
identifies all 865 known computer viruses and their variants.
Some viruses have been modified so that more than one "strain"
exists. Counting such modifications, 1,561 viruses exist.
All known viruses infect one or more of the following
areas: the hard disk partition table (alias Master Boot Record);
the Boot Sector of disks; or one or more executable files on
the system. Executable files include operating system files,
.COM files, .EXE files, overlay files, or any other files
containing program code. A virus that infects more than one
area, such as a boot sector and an executable file is called
a multipartite virus.
OS2SCAN checks files, subdirectories, diskettes or entire
systems for pre-existing computer virus infections. It will
identify the virus infecting the system and the area where it
was found, giving the name of the virus as well as the I.D.
code used with CLEAN-UP to remove it.
Infected files can be removed using the /D switch in OS2SCAN
to erase the file, or with the CLEAN-UP universal virus removal
(disinfection) program. CLEAN-UP is recommended because in most
cases it will eliminate the virus and fully restore infected
programs or system areas to normal operation. CLEAN-UP is
available in both DOS and OS/2 versions.
The accompanying VIRLIST.TXT file lists describes all
viruses identified by OS2SCAN and their associated I.D. codes
for removal by CLEAN-UP.
OVERVIEW (Unknown and New Virus Detection)
OS2SCAN has three separate methods of detecting unknown and
new viruses:
■ Validation codes which can be periodically checked against
to look for the changes made by a virus to files or system
areas.
■ Generic and Family virus detectors to look for new viruses
which are derivatives of older viruses.
■ External virus signatures to insert new virus signature
strings on a temporary basis to OS2SCAN.
OS2SCAN FOR OS/2 Version 9.0V99 Page 4
SYNOPSIS (technical description of known virus detection)
OS2SCAN detects known viruses by searching the system for
strings (sequences of bytes) unique to each computer virus and
reporting their presence if found. For viruses which encrypt or
cipher their code so that every infection of the virus is
different, OS2SCAN uses detection algorithms (programs) that work
by statistical analysis, heurstics, or code disassembly.
SYNOPSIS (technical description of new/unknown virus detection)
OS2SCAN checks for new or unknown viruses by comparing
files against previously-recorded validation (checksum) data.
OS2SCAN has two levels of validation which are stored in three
separate ways:
■ A simple 10-byte long validation checksum may be appended
to .COM and .EXE files. If a file has been modified, it
no longer matches the checksum and OS2SCAN reports the
file may be infected. (/AV, /CV, /RV switches)
■ An enhanced 52-byte validation and recovery data checksum
can also be created. This can be appended to the end of
files like the 10-byte checksum, or stored in a separate
log file which can be offline (e.g., on floppies) for
recovery purposes. CLEAN-UP can restore infected files,
partition tables, or boot sectors using this information.
(/AG, /CG, /RG switches and /AF, /CF, /RF switches)
NOTE: OS2SCAN does NOT add codes to the partition table, boot
sector, or system files. Instead, a separate hidden file
will be created in the root directory named SCANVAL.VAL
containing data for these areas.
NOTE: Files which are self-checking (e.g., Lotus 1-2-3) should
not be validated with the /AV (Add Validation) or /AG
(Add Generic) switches which modify files. Instead, use
the /AF (Add File) switch.
OS2SCAN also checks for new or unknown viruses by searching
for Generic or Family virus strings. These are strings that
have been found repeatedly in different viruses. Since virus
writers may use the older pieces of code for new viruses, this
allows OS2SCAN to detect viruses which have not been written yet.
OS2SCAN can be updated to search for new viruses by an
External Virus Data File, which allows the user to input new
search strings for viruses. (/EXT switch)
OS2SCAN FOR OS/2 Version 9.0V99 Page 5
AUTHENTICITY
Before using OS2SCAN for the first time, verify that it has
not been tampered with or infected by a virus by using the
enclosed VALIDATE for OS/2 (OS2VAL.EXE) program. For
instructions on using OS2VAL, please read the OS2VAL.DOC file.
The validation results for Version 9.0V99 should be:
FILE NAME: OS2SCAN.EXE
SIZE: 178,352
DATE: 12-09-1992
FILE AUTHENTICATION
Check Method 1: 78A3
Check Method 2: 10CA
NOTE: If you run VALIDATE.COM for DOS against OS2SCAN.EXE, a
different Check Method 1 value will be returned. Do not
use VALIDATE.COM to validate OS2SCAN.EXE
If your copy of OS2SCAN differs, it may have been damaged.
Always obtain your copy of OS2SCAN from a known source. The
latest version of OS2SCAN and validation data for OS2SCAN.EXE
can be obtained from McAfee Associates' bulletin board system
at (408) 988-4004 or from the McAfee Virus Help Forum on
CompuServe (GO MCAFEE), or the mcafee.COM anonymous ftp site on
the Internet.
OS2SCAN performs a self-check when run. If OS2SCAN has
been modified in any way, a warning will be displayed and the
user will be prompted to either continue or quit. OS2SCAN can
still check for viruses. However, if OS2SCAN reports that it
has been damaged, it is recommended that a new copy be obtained.
Beginning with Version 72, all of McAfee Associates'
VIRUSCAN series are archived with PKWare's PKZIP Authentic File
Verification. If you do not see an "-AV" after every file is
unzipped and receive the "Authentic Files Verified! # NWN405
Zip Source: McAFEE ASSOCIATES" message when you unzip the files
then do not use them. If your version of PKUNZIP does not have
verification ability, then this message may not be displayed.
Please contact us if you believe tampering has occurred to the
.ZIP file.
OS2SCAN FOR OS/2 Version 9.0V99 Page 6
COMMAND SUMMARY
IMPORTANT NOTE: WRITE PROTECT YOUR FLOPPY DISK BEFORE SCANNING
TO PREVENT INFECTION OF THE OS2SCAN PROGRAM.
OS2SCAN checks files and other areas of the system that
can contain a computer virus. When a virus is found, OS2SCAN
identifies the virus and the file or system area where it was
found.
OS2SCAN examines files based on their extension. The default
extensions supported by OS2SCAN are .APP, .BIN, .COM, .EXE,
.OV?, .PGM, .PIF, .PRG, .SWP, .SYS, and .XTP. Additional
extensions can be added with the /E option, or use the /A to
check all files.
Valid options for OS2SCAN are:
OS2SCAN {drive(s)} {options}
{drive(s)} - Indicates a drive or drives to be scanned
Options are:
\ - Scan root directory and boot area only
/? /H or /HELP - Displays help screen
/A - Scan all files, including data, for viruses
/AD - Scan all local drives for viruses
/AF {filename} - Store recovery & validation data to {filename}
/AG {filename} - Add recovery & validation data to files
EXCEPT for those listed in {filename}
/AV {filename} - Add validation codes to files EXCEPT for
those listed in {filename}
/BELL - Beep whenever a virus is found
/CERTIFY - List files that do not have a validation code
/CF {filename} - Check for viruses using recovery & validation
data stored in {filename}
/CG - Check recovery & validation data on files
/CV - Check validation codes on files
/D - Overwrite and delete infected files
/DATE - Save the date and time OS2SCAN was last run
(use /SHOWDATE to display)
/E .xxx .yyy - Scan overlay extensions .XXX and .YYY
/EXT {filename} - Scan using external virus data from {filename}
/FAST - Speed up OS2SCAN's output
(see below for specifics)
/FR - Display all messages in French
/HISTORY {fname} - Create infection log {fname} appending to old log
OS2SCAN FOR OS/2 Version 9.0V99 Page 7
/MANY - Scan multiple disks
/NLZ - Skip internal scan of LZEXE-compressed files
(DOS executables only)
/NOBREAK - Disable Ctrl-C and Ctrl-Brk during scanning
/NOEXPIRE - Do not display expiration notice
/NOPAUSE - Disable screen pause when scanning
/NPKL - Skip internal scan of PKLITE-compressed files
(DOS executables only)
/REPORT {fname} - Create infection log {fname} deleting the old log
/RF filename - Remove recovery & validation data stored
/RG - Remove recovery & validation data from files
/RV - Remove validation codes from specified files
/SAVE - Save specified options as new default options
/SHOWDATE - Display the date and time OS2SCAN was last run
(use /DATE to save date and time)
/SP - Display all messages in Spanish
/SUB - Scan all subdirectories inside a subdirectory
@{filename} - Scan using options from {filename}
[This space left intentionally blank.]
OS2SCAN FOR OS/2 Version 9.0V99 Page 8
OPTIONS
Following is a detailed description of OS2SCAN's options.
Please note the /AF and /AG switches modify executable files.
This may cause other anti-viral programs to generate a warning.
/A - This option checks all files on the drive scanned and also
examines a greater portion of files. This substantially
increases the time required to scan disks and also increases
OS2SCAN's ability to detect viruses in overlay files. It is
recommended this switch only be used when installing software
or if a file-infecting virus has been found. This option takes
priority over the /E option.
/AD - This option scans all local hard disk drives for viruses.
No drives need to be listed when the /AD switch is used.
NOTE: If network drives exist, OS2SCAN will attempt to access
them when run with the /AD switch and fail.
/AF {filename} - This option logs recovery and validation
data for .COM and .EXE files, boot sector, and partition table
of a disk to a user-specified file. The log file size is about
20Kb per 1,000 files validated. Recovery from a virus using the
/AF information requires the CLEAN-UP program.
/AG {filename} - This option allows the user to store recovery
and validation data for .COM and .EXE files, boot sector, and
partition table of a disk. Recovery information adds 52 bytes
to files. The recovery information for the partition table,
boot sector, COMMAND.COM and system files is stored separately
in a hidden file called SCANVAL.VAL in the root directory of the
drive being scanned. {filename} is an optional ASCII text file
listing files NOT to add recovery and validation data to (see
NOTE below). Recovery from a virus using the /AG information
requires the CLEAN-UP (CLEAN.EXE) program.
/AV {filename} - This option allows the user to store validation
codes for .COM and .EXE files, boot sector, and partition table
of a disk. Validation information adds 10 bytes to files. The
validation codes for the partition table, boot sector, system
files and COMMAND.COM is stored separately in a hidden file
named SCANVAL.VAL in the root directory of the drive being
scanned. {filename} is an optional ASCII text file listing the
files NOT to add validation codes to (see note below).
OS2SCAN FOR OS/2 Version 9.0V99 Page 9
NOTE: Files which are immunized against viruses or contain
self-modifying code should not have validation codes
added to them. To prevent OS2SCAN from adding validation
codes to these files, a validation exception list must be
created with the path and filename of each file NOT to be
validated listed on each line (only one filename for each
line). To put a comment in, start the line with an "*"
character. This sample file contains a list of programs
NOT to validate:
*LIST OF FILES NOT TO USE /AV OR /AG OPTIONS WITH
*
*This is Nantucket Corp's database program, Clipper
D:\CLIPPER\BIN\CLIPPER.EXE
*This is Lotus Development Corp's spreadsheet program, 1-2-3
D:\123\123.COM
*This is MS-DOS 5.00's self-modifying program, SETVER
D:\DOS\SETVER.EXE
*PKWare's data compression programs already perform a self-check
D:\PKWARE\PKLITE.EXE
D:\PKWARE\PKZIP.EXE
D:\PKWARE\PKUNZIP.EXE
*Stac Technologies hard disk swapping program
D:\SWAPVOL.COM
*Symantec's Norton Utilities V6.01 disk caching program
D:\NORTON\NCACHE.EXE
*WordStar Corp's word processor is self-modifying
D:\WORDSTAR\WS.EXE
The validation exception list should be an ASCII or DOS
text file. If a word processor is used to create the list, be
sure to save the file as ASCII or DOS Text.
/BELL - This option tells OS2SCAN to beep when a virus is found.
/CERTIFY - This option will audit a system for files that have
validation codes added to them with the /AG or /AV switches.
Files that have no validation code will be reported as being
uncertified by OS2SCAN.
/CF {filename} - This option checks recovery and validation data
stored by the /AF option in {filename}. If a file or system
area has changed, OS2SCAN reports that a viral infection may
have occurred. Using the /CG option adds about 25% more time to
scanning.
OS2SCAN FOR OS/2 Version 9.0V99 Page 10
/CG - This options checks recovery and validation data added by
the /AG option. If a file or system area has changed, OS2SCAN
reports that a viral infection may have occurred. Using the /CG
option adds about 25% more time to scanning. This option takes
priority over the /CV option.
/CV - This option checks validation codes inserted by the /AV
option. If a file or system area has been changed, OS2SCAN will
report that the file or system area has been modified and a
viral infection may have occurred. Using the /CV option adds
about 20% more time to scanning.
NOTE: Dual Boot systems change the Boot Sector between DOS and
OS/2 depending on which operating system is currently
active. This will cause OS2SCAN to report that the boot
sector has been modified.
/D - This option tells OS2SCAN to prompt the user to overwrite
and delete an infected files. Files erased by the /D option
can not be recovered. If the CLEAN-UP program is available,
it can be used to disinfect the file. Partition table and boot
sector viruses can not be removed by the /D option and require
the CLEAN-UP virus removal program.
/DATE - This option stores the time and date OS2SCAN was last
executed. This is done by changing the date on the SCANVAL.VAL
file. If no SCANVAL.VAL file exists, OS2SCAN will create a 0-byte
long file in the currently-logged directory.
/E .xxx .yyy - This option allows an additional extension or set
extensions to be scanned. Extensions should include a period "."
character and be separated by a space after the /E. Up to three
extensions may be added with the /E. For more extensions, use
the /A option instead.
/EXT {filename} - This option tells OS2SCAN to search for viruses
using virus search strings from ASCII text file {filename}, in
addition to the viruses that OS2SCAN looks for. For instructions
creating an external virus data file, refer to Appendix A.
NOTE: The /EXT option provides users with the ability to add
strings for detection of viruses on an interim or
emergency basis. When used with the /D option, it will
overwrite-and-delete infected files. This option is not
for general use and should be used with caution.
OS2SCAN FOR OS/2 Version 9.0V99 Page 11
/FAST - This option speeds OS2SCAN up by displaying less on the
the screen, skipping checking inside of LZEXE- and PKLITE-
compressed files (DOS only), and examining a smaller portion of
files during scanning. This may reduce the accuracy of OS2SCAN.
/FR - This option tells OS2SCAN to display all messages in
French instead of English. This option cannot be used with the
/SP (Spanish) option.
/HISTORY {filename} - This option saves the output of OS2SCAN
to {filename} in ASCII text file format. If {filename} exists,
OS2SCAN will add the results of the current scan to the end.
/MANY - This option is used to scan multiple diskettes placed
in a given drive. If the user has more than one floppy disk to
check for viruses, the /MANY option will allows the user to
check disks without having to re-run OS2SCAN multiple times.
/NLZ - This option tells OS2SCAN not to look inside files
compressed with LZEXE, a file compression program for DOS
.EXE files. OS2SCAN will still check LZEXE-compressed files for
viruses that may have become infected after LZEXE compression.
/NOBREAK - This option prevents Ctrl-C or Ctrl-Brk from aborting
the scanning process.
/NOEXPIRE - This option prevents OS2SCAN from displaying a
warning message after 7 months warning that it may no longer be
current with respect to known computer viruses.
/NOPAUSE - This option disables the "More? (H = Help )" prompt
displayed when OS2SCAN fills up a screen with 24 lines of text.
This allows OS2SCAN to run on PC's with severe infections without
requiring operator assistance.
/NPKL - This option tells OS2SCAN not to look inside files
compressed with PKLITE, a file compression program for DOS .EXE
files. OS2SCAN will still check PKLITE-compressed files for
viruses that may have become infected after PKLITE compression.
/REPORT {filename} - This option saves the output of OS2SCAN
to {filename} in ASCII text file format. If {filename} exists,
OS2SCAN will erase it and replace with the current scan results.
/RF {filename} - This option removes recovery and validation
data from log file {filename} created by the /AF option.
OS2SCAN FOR OS/2 Version 9.0V99 Page 12
/RG - This option removes validation and recovery data from a
file or files validated with the /AG option. Using the /RG
switch against a drive removes the SCANVAL.VAL file. This
option can not be used with the /AG option.
/RV - This option removes validation codes from a file or files
validated with the /AV option. Using the /RV switch against a
drive removes the SCANVAL.VAL file. This option can not
be used with the /AV option.
/SAVE - This option stores any listed options for subsequent
executions of OS2SCAN. The options are stored by creating a
file named OS2SCAN.INI in the same directory as OS2SCAN.EXE. For
example, the command:
OS2SCAN /NOMEM /REPORT C:\OS2SCAN.LOG /NOPAUSE /SAVE
saves the default options to /NOMEM, /REPORT C:\OS2SCAN.LOG and
/NOPAUSE and will cause OS2SCAN to use these options the next
time it is run. If OS2SCAN is run with only the /SAVE switch,
the OS2SCAN.INI file is removed. If you wish to use more than one
set of switches with OS2SCAN, use the @{filename} option
instead.
/SHOWDATE - This option displays the time and date OS2SCAN was
last run. No virus checking is performed.
NOTE: When run with /SHOWDATE, OS2SCAN only displays the last run
date. Viruses will *NOT* be checked for.
/SP - This option tells OS2SCAN to display all messages in Spanish
instead of English. This option cannot be used with the /FR
(French) option.
/SUB - This option scans all subdirectories inside a
subdirectory. Previously, OS2SCAN would only recursively check
subdirectories if a drive was scanned at the root level (e.g.,
C:). Do not use the /SUB switch if you are scanning a drive
from the root level.
@{filename} - This option allows the user to run OS2SCAN with
a configuration file listing the options and drives OS2SCAN is
to check. Options need to be separated by a space, while drives
(disks, subdirectories, or files) need to be listed on separate
lines. A sample file might look like this:
/A /BELL /CV /REPORT C:\OS2SCAN\OS2SCAN.LOG
C:
The first line contains the OS2SCAN options while other lines
list the names of disks, subdirectories, or files to scan. The
file should be an ASCII text file.
OS2SCAN FOR OS/2 Version 9.0V99 Page 13
EXAMPLES
The following examples show different option settings:
OS2SCAN C:
To scan drive C:
OS2SCAN A:R-HOOPER.EXE
Scans file "R-HOOPER.EXE" on drive A:
OS2SCAN A: /A /CV
Scans all files and checks validation codes for unknown
viruses on drive A:.
OS2SCAN B: /D /A
Scans all files on drive B: and prompt for erasure of
any infected files, if found.
OS2SCAN C: D: E: /AV
Scan for viruses, add validation codes to files on
drives C:, D:, and E:.
OS2SCAN C: D: /A /FR
Scan all files on drives C: and D: for viruses, and
display all messages in French.
OS2SCAN C: D: /E .WPM .COD
Scans drives C: and D:, including .WPM and .COD files
OS2SCAN C: /EXT A:SAMPLE.ASC /BELL
To scan drive C: for known computer viruses and also
for viruses added by the user via the external virus
data file option, and beep whenever a virus is found.
OS2SCAN C: /NOPAUSE /REPORT A:INFECTN.RPT
To scan drive C: without stopping, and create a log
file INFECTN.RPT on drive A:
OS2SCAN E:\DOWNLOADS /SUB
To scan all subdirectories under the directory
DOWNLOADS on drive E:
OS2SCAN C: D: E: /FAST /CERTIFY
To perform a fast scan of drives C:, D:, and E: and
check for any files that do not have validation codes.
OS2SCAN @C:\SCANOPTN.LST
To run OS2SCAN using configuration file SCANOPTN.LST
located in the root directory of drive C:.
OS2SCAN /AD
Scan all hard drive partitions for viruses.
OS2SCAN FOR OS/2 Version 9.0V99 Page 14
VIRUS REMOVAL
What do you do if a virus is found? You can contact McAfee
Associates for help, their authorized agents, or use the CLEAN-UP
program. CLEAN-UP is available for DOS (CLEAN.EXE) and OS/2
(OS2CLEAN.EXE).
McAfee Associates can be reached by BBS, CompuServe, FAX,
Internet, or Telephone and there is no charge for support calls
to McAfee Associates (Authorized agents may charge normal McAfee
Associates consulting rates.).
The CLEAN-UP universal virus disinfection program can
disinfect virtually all reported computer viruses. It is
updated with each release of the OS2SCAN program to remove new
viruses. CLEAN-UP can be downloaded from McAfee Associates'
BBS, the McAfee Virus Help Forum on CompuServe, and the
mcafee.COM and WSMR-SIMTEL20.Army.Mil sites on the Internet, or
from any of the agents' BBSes listed in the enclosed AGENTS.TXT
text file.
It is strongly recommended that you get experienced help in
dealing with viruses if you are unfamiliar with anti-virus
software and methods. This is especially true for 'critical'
viruses and partition table/boot sector infecting viruses as
improper removal of these viruses can result in the loss of
all data and the use of the infected disk(s).
Before removing a boot sector or partition table-infecting
virus, it is recommended that you cold boot the infected PC from
a clean DOS disk and backup any critical data.
For qualified assistance in removing a virus, contact
McAfee Associates directly or any of the Authorized Agents in
your area. Agents may charge McAfee Associates' normal consult
rates for their services.
If you wish to remove a file-infecting virus manually, cold
boot the PC from a clean (virus-free) OS/2 boot diskette and run
OS2SCAN with the /A and /D switches to erase all infected files.
Any files removed in this manner can not be recovered.
OS2SCAN FOR OS/2 Version 9.0V99 Page 15
REGISTRATION
A registration fee of US$35.00 is required for the use of
OS2SCAN by individual home users. Registration entitles the
holder to unlimited free upgrades from McAfee Associates' BBS,
the Internet, and the McAfee Virus Help Forum on CompuServe as
well as technical support for one year. When registering, a
diskette containing the latest version may be requested for an
additional US$9.00. Only one diskette mailing will be made.
Registration is for home users only and does not apply to
businesses, corporations, organizations, government agencies, or
schools, which must obtain a license for use. Contact McAfee
Associates directly or an Authorized Agent for more information.
TECH SUPPORT
For fast and accurate help, please have the following
information ready when you contact McAfee Associates:
- Program name and version number.
- Type and brand of computer, hard disk, plus any
peripherals.
- Version of OS/2 plus any device drivers in use.
- Printouts of your AUTOEXEC.BAT and CONFIG.SYS files.
- The exact problem you are having. Please be as
specific as possible. Having a printout of the
screen and/or being at your computer will be helpful.
McAfee Associates can be contacted by BBS, CompuServe, FAX, or
InterNet 24 hours a day, or by telephone at (408) 988-3832,
Monday through Friday, 7:00AM to 5:30PM Pacific Time.
If you are overseas, you can contact a McAfee Associates
Authorized Agent. Agents are located in over 50 countries
around the world and provide local sales and support for our
software. Please refer to the AGENTS.TXT file for a complete
list of McAfee Associates Agents.
OS2SCAN FOR OS/2 Version 9.0V99 Page 16
OBTAINING THE LATEST VERSION OF McAFEE ASSOCIATES PROGRAMS
McAfee Associates regularly updates the OS2SCAN series
of programs every 4 to 6 weeks to add new virus detectors,
new options, and fix reported bugs. To distribute these new
versions, we run a multi-line BBS, CompuServe Forum, and
Internet node.
BBS ACCESS
Our 25-line BBS is accessible 24 hours a day, 365 days a
year, except for scheduled downtime and maintenance. All lines
run US Robotics Courier HST Dual Standard ASL modems operating
from 1,200bps to 14,400bps with line settings of 8 data bits, no
parity, and one stop bit.
THE McAFEE VIRUS HELP FORUM ON COMPUSERVE
We are now sponsoring the McAfee Virus Help Forum on
CompuServe. To reach the McAfee Virus Help Forum type GO MCAFEE
at any CompuServe prompt. A free introductory membership is
available. For more information, please read the enclosed
COMPUSER.NOT file.
INTERNET ACCESS TO McAFEE ASSOCIATES SOFTWARE
The latest versions of McAfee Associates' anti-viral
software is now available by anonymous ftp (file transfer
protocol over the Internet from the site mcafee.COM. If
your domain resolver does not support names, use the IP#
192.187.128.1. Enter "anonymous" for your user I.D. and
your own email address for the password. Programs are
located in the pub/antivirus directory. If you have any
questions, please send email to support@mcafee.COM
McAfee Associates' anti-viral software may also be
found at the Simtel20 archive site WSMR-SIMTEL20.Army.MIL
in the PD1:<MSDOS.TROJAN-PRO> directory and its associated
mirror sites WUARCHIVE.WUSTL.EDU (US), NIC.SWITCH.CH (Swiss),
NIC.FUNET.FI (Finland), SRC.DOC.IC.AC (UK), and
RANA.CC.DEAK.OZ.AU (Australia).
OS2SCAN FOR OS/2 Version 9.0V99 Page 17
APPENDIX A: Creating a Virus String File with the /EXT Option
NOTE: The /EXT option is intended for emergency and research
use only. It is a temporary method for identifying new
viruses prior to the subsequent release of OS2SCAN. A
thorough understanding of viruses and string-search
techniques is advised for using this option. A string
length of 10 to 15 bytes is recommended.
The External Virus Data file should be created with an
editor or a word processor and saved as an ASCII text file. Be
sure each line ends with a Carriage Return/Line Feed pair.
The virus string file uses the following format:
#Comment about Virus_1
"aabbccddeeff..." Virus_1_Name
#Comment about Virus_2
"gghhiijjkkll..." Virus_2_Name
.
.
"uuvvwwxxyyzz..." Virus_n_Name
Where aa, bb, cc, etc. are the hexadecimal bytes that you wish
to scan for. Each line in the file represents one virus. The
Virus Name for each virus is mandatory, and may be up to 25
characters in length. The double quotes (") are required at the
beginning and end of each hexadecimal string.
OS2SCAN will use the string file to search the Master Boot
Record (partition table), Boot Sector, System files, all .COM
and .EXE files, and overlay files with the extension .APP, .BIN,
.COM, .EXE, .OV?, .PGM, .PIF, .PRG, .SWP, .SYS, and .XTP.
Virus strings may contain wild cards. The two wildcard
options are:
FIXED POSITION WILDCARD
The question mark "?" may be used to represent a wildcard
in a fixed position within the string. For example, the string:
"E9 7C 00 10 ? 37 CB"
would match "E9 7C 00 10 27 37 CB", "E9 7C 00 10 9C 37 CB", or
any other similar string, regardless of the fifth byte.
OS2SCAN FOR OS/2 Version 9.0V99 Page 18
RANGE WILDCARD
The asterisk "*", followed by range number in parentheses
"(" and ")" is used to represent a variable number of adjoining
random bytes. For example, the string:
"E9 7C *(4) 37 CB"
would match "E9 7C 00 37 CB", "E9 7C 00 11 37 CB", and
"E9 7C 00 11 22 37 CB". The string "E9 7C 00 11 22 33 44 37 CB"
would not match since the distance between 7C and 37 is greater
than four bytes. You may specify a range of up to 99 bytes.
Up to 10 different wildcards of either kind may be used in one
virus string.
COMMENTS
A pound sign "#" at the begining of a line will denote a
comment. Use this for adding notes to the external virus data
file. For example:
#New .COM virus found in file FRITZ.EXE from
#Schneiderland on 01-22-91
"53 48 45 45 50" Fritz-1 [F-1]
gives a description of the virus, name of the infected file,
where and when it was found, etc.
APPENDIX B: Miscellaneous Application Notes
OS2SCAN VALIDATION CODES
If you have installed any new software or programs on your
system, and are running OS2SCAN or VSHIELD for DOS with the /CF,
/CG, or /CV validation codes options, you will need to reinstall
validation codes to the new files with the /AF, /AG, or /AV
add validation codes options of OS2SCAN. In addition, the
SCANVAL.VAL hidden file containing validation codes for the
partition table, boot sector, COMMAND.COM, and system files may
have to be replaced (unhide the file with the ATTRIB command
and then delete it).
The quickest way to update the validation codes is to
remove all validation codes from the hard disk and then add them
back by running OS2SCAN with the /RV and then the /AV options.
NOTE: This applies to any new version of DOS, as well as any
programs which you install on your system.
OS2SCAN FOR OS/2 Version 9.0V99 Page 19
IMPORTANT NOTICE - PLEASE READ!
Due to the nature of anti-virus software, the slight chance
exists that a virus may be reported in a file that is not
infected by that virus.
If you receive a report of a virus infection which you believe
may be in error, please contact McAfee Associates by telephone
at (408) 988-3832, by fax at (408) 970-9727, or upload the file
to our BBS at (408) 988-4004 along with your name, address,
daytime telephone number, and electronic mail address, if any.