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OFF!.DOC
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1993-11-06
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OFF! v01.04.00 (06 NOV 1993) -- checks for & removes the Oƒƒspring V0.89 virus
Copyright (c) 1993, Professional Software Engineering
All Rights Reserved.
This program is for FREE distribution only.
A program to remove the Oƒƒspring V0.89 virus from files. IT IS NOT INTENDED
TO DETECT AND REMOVE OTHER VIRUSES -- ONLY THE "Oƒƒspring V0.89" VIRUS. This
program is very fast at what it does -- thousands of hard drive files can be
scanned in a single minute.
Off! IS NOT A GENERAL PURPOSE VIRUS DETECTION/REPAIR UTILITY.
There is currently another program out called FindVirus (distributed as
FINDV100.ZIP and FINDV110.ZIP as of this writing) which claims "may help in
identifying a virus currently undetected by SCANV, Central Point, Off! and
other scanners". The reference to Off! appears to have been made in error,
since the FindVirus program does not look for the "Oƒƒspring V0.89" virus, but
a different variant -- the "ASeXual V0.99" virus (which NEUTER, another program
by the author of Off!, will find and disinfect).
Off! first reports whether the virus is in memory or not. If it is, the
program will terminate with instructions on how to properly go about removing
the virus -- you run the risk of spreading the virus just by running programs!
This program itself is immune to infection by the Oƒƒspring V0.89 virus. If
the system does not have the virus in memory, the program will then scan for
all files in the given drive/directory specification and eradicate the virus
whenever it is encountered.
Legal Disclaimer
================
This program was produced and is provided FREE as a fix for a virus. The
author of this program makes no warranty that this program will fix your
problem, nor that this program will recover any or all of your data. It is
possible that certain circumstances may cause this program to erase
information. In no event can the author be held liable for damages resulting
from the use of this program. Every effort has been made to positively
identify a file as being infected with the virus before attempting to recover a
file from the virus.
This file should have come to you inside a PKZIP archive with authentication
that should have looked something like this:
-----------------------------------------------------------------------------
PKUNZIP (R) FAST! Extract Utility Version 2.04g 02-01-93
Copr. 1989-1993 PKWARE Inc. All Rights Reserved. Registered version
PKUNZIP Reg. U.S. Pat. and Tm. Off.
■ 80486 CPU detected.
■ EMS version 4.00 detected.
■ XMS version 3.00 detected.
■ DPMI version 0.90 detected.
Searching ZIP: OFF!_104.ZIP
Inflating: FILE_ID.DIZ -AV
Inflating: OFF!.COM -AV
Inflating: OFF!.DOC -AV
Authentic files Verified! # DQP160
Professional Software Engineering
-----------------------------------------------------------------------------
There should be only two files in the archive, and both should have the
authentication information. If not, check with the source you obtained this
file from.
Parameters:
A drive or path on the commanline to indicate where to start scanning for the
virus. A dot "." represents the current directory. All files will be checked,
reguardless of assumed file type. It will find and recurse into hidden
directories as well.
Examples:
OFF! C: Disinfects the entire C: drive. Go boil a pot of tea
while you wait, it may take awhile.
OFF! . Disinfects all files in the current directory, and all
directories underneath it.
OFF! D:\UTILS Disinfects all files under the UTILS directory on D:
On exit, there will be a DOS errorlevel of 1 if the virus was encountered in
memory, 2 if in a disk file, and 0 if the virus was not found.
Release history:
v01.00.03 (17 OCT 1993)
* Original public release. Scans a single specified directory with a given
filespec (such as *.*). Does not perform directory recursion. Completely
recovers files from the virus.
v01.01.00 (19 OCT 1993)
* Improved speed, and added directory recursion. The commandline syntax also
differs.
v01.02.00 (19 OCT 1993)
* Corrected a problem in the display of the current directory being processed
(an error in v01.01.00). Was displaying the drive letter that was current when
the program was run, rather than the one specified. This had no effect on
program operation.
v01.03.00 (24 OCT 1993)
* detection of Novell NetWare, adding special file handling to avoid problems
with Transaction Tracking System (TTS) files which Novell won't let the program
even look at without causing the program to be terminated by a network error.
* Output format to be easier to read with less clutter -- only files with
viruses or which could not be processed are left on the screen, all others
scroll by re-using the same line.
* It identifies the drive being scanned as a local drive (real hard disk or
floppy drive), or as a network/remote drive (CD-ROM, actual network drive, and
possibly some compressed hard drives). Local drives don't incur the additional
overhead of checking for the special Novell files even if Novell is detected as
being present.
* Also noted the appearance of FINDV (v1.00 and v1.10) from ExecNet Information
Systems. The program makes reference to Off!, lifts text directly from the
virus characteristics text below (verbatim), and doesn't even fix files -- it
merely has the option of deleting them automatically. Boy, you know you've
arrived when people start copying stuff from your freeware.
* Updated the docs a bit.
v01.04.00 (06 NOV 1993)
* Found a problem in a derivative of this (NEUTER), and fixed it there, and
fixing it here too -- if the only infections are in .EXE stubs, the errorlevel
is not reported properly. Also added message display at program termination to
indicate whether any viruses were found (in case the messages had scrolled off
the top of the screen).
Virus characteristics:
======================
These characteristics were determined by actually examining the viral code, and
not by trial and error logging of changes to a system.
Infected file date and times will remain unchanged. In the case of .COM stubs
for .EXE files, the information will be the same as for the .EXE file they are
stubbing, and the new .COM file will be hidden. It does not infect COMMAND.COM
or 0 byte files.
Virus is self-encrypting, and uses a cycle of register changes for the
decryption code (so the non-encrypted code is not consistent).
The growth of an infected file will range from +1395 to +1495 bytes.
Infections occur when programs are run, and 5 files will be infected (if you
run 5 programs (whether they are infected or not), 25 new files will be
infected). Note that some programs run others internally ("overlays"), and
these operations count as running a program as well.
The virus takes over the DOS critical error handler when it goes to infect a
series of files, so if you have a write protected floppy in the drive, you will
not get an error message from DOS. Read-only files and hidden files are not
safe from the virus.
There are two special filenames in the program, and both appear to be
anti-viral data files:
CHKLIST.*
ANTI-VIR.DAT
Any time a program is run, the directory where the program is located is
checked for these two filespecs, and if they are found, they are made into 0
length files and deleted. It does not matter if they are hidden or readonly.
From initial inspection, if the date is the 9th day of any month, the virus
message ("Oƒƒspring V0.89 virus") will be displayed to the screen (via a DOS
call -- which means that if the output of the infected program was being
redirected, you will not actually see the message), and if you have a printer
online, the screen will be repeatedly dumped to the printer. There will be a
beep between each attempted screen dump to printer, and a short delay. The
process will repeat (the virus text will not be redisplayed). The keyboard
LEDs will be flashing during this period, and any attempt to reboot will fail,
since the keyboard data is being manipulated by the virus. Because there have
not been reports of this virus in past months, it is probably safe to infer
that the virus is only about a month old as of this writing.
The first time it is run within a system, it will load itself resident,
latching into the DOS INT 21h vector, waiting for programs to be run.
Thanks to Al Kalian, Sysop of Palladin in Marin County, California for
discovering this virus locally during his standard check of files before
posting for users to download -- because of his dilligence, this virus might be
erradicated before it spreads far. Thanks also for his fine recommendations
for and testing of the OFF! program, especially recent testing of Network
compatibility.
Also, thanks to Thomas Tuerke, Sysop of GravesEnd in Cotati, California for his
help in directing me to the proper reference for a function to truncate a file
(Mr. Tuerke is the author of a 1701 virus disinfection utility).
While this program is FREE, the author wouldn't turn down donations from anyone
who feels inclined to send him money for his work -- especially those who find
that this utility recovered their files from the virus. A number of hours went
into reverse-engineering the virus and developing a fix (and testing it), yet
the author did not develop this program out of a need to remove the virus from
his own equipment, which was never infected to begin with. If you feel like
sending a donation for my work, please make the cheque or money order (drafted
on a U.S. bank) payable to: "Sean B. Straw", and send it to the address below.
$5 to $10 is suggested IF YOU FEEL LIKE PAYING FOR THIS PROGRAM. You don't
have to.
Note that "FREE distribution" implies that you should not have paid ANYTHING to
anyone to get this program -- by the time a shareware diskette house gets this
program into production on floppies, McAfees SCAN and CLEAN programs should
have been updated with support for this virus. If you paid anyone money for
this program (other than the author), demand your money back, and if you get
the line "The $5.99 you paid was for the diskette and duplication", I would
heartily suggest checking out getting or using a modem (if you already have
one) -- a cheap 2400 baud internal would cost you less to buy than 8-10 such
shareware disks, though I'd recommend at least a 9600 baud modem. A modem will
open up a whole new world of computing to you.
While at this time I have no relationship with McAfee Associates, and they do
not support this program, they do have a fine line of software, including a
Virus scanner and disinfector. Their BBS number is (408) 988-5190
And if you were hit by the virus, you might consider seeing to it that you have
an updated version of whatever anti-virus package you normally use -- or you
should go buy a package to suit your needs.
About the author:
=================
Professional Software Engineering is a developer of system enhancement
utilities and a variety of anti-virus tools. We also provide custom systems
programming services in assembler and C, and perform password recovery for
files in PKZIP files which have been encrypted.
Professional Software Engineering
Post Box 2395
San Rafael, CA 94912-2395
(415) 459-7401