Update on Computer Viruses and Prevention Strategies

Jerry Isaacson

Over 7,000 computer viruses and variants have been identified by 
the developers of anti-virus software, and the number grows at a 
rate of 100 to 150 per month. Most viruses aren't a threat because 
they haven't spread or don't work. Even so, every computer user 
needs to take precautions. In January, the number of "viruses in the 
wild" -  viruses reported by at least three virus researchers - 
grew to 183.

Viruses Reported at MIT 
Some of those "viruses in the wild" found their way to MIT over the 
past year. According to the Information Security Office (ISO), the 
culprits included 

AntiCMOS.A 
AntiEXE.A 
Form.A
Ripper
Sat_Bug.Natas
Stoned.Angelina
Stoned.Empire.Monkey.B
WinWord.Concept

While most of these viruses are nuisances, some, like Ripper, can 
destroy both your data and local backups.

Trendsetters
The well-known WinWord.Concept virus underscores two new trends 
in viruses: the ability to infect data files rather than programs, and 
the ability to run on multiple platforms. The Concept virus uses the 
macro capabilities built into Microsoft Word to infect files, and runs 
under DOS, Windows, and Macintosh versions of Word.

In another cross-platform twist, Macintoshes running DOS/Windows 
emulation have become susceptible to DOS/Windows viruses.

An Ounce of Prevention
Viruses are out there, and they are learning new tricks. As custodian 
of your computer, you have a choice. You can install anti-virus 
software, or you can leave your computer open to attack. A virus 
infection will, at the least, require hours of cleanup time. An infection 
caused by a boot sector virus (which can be found on any disk, even 
those containing only data) will require cleaning all the systems in 
your area that may have been infected. To prevent reinfection, you'll 
also need to check every diskette that may have been a source.

It's far easier to do the right thing. Anti-virus software offers a 
simple, effective means of protection. The ISO provides such software 
via net-dist and through its Web page at

http://web.mit.edu/security/www

Once you've installed anti-virus software, be sure to keep it current. 
Check the ISO Web page or net-dist for updates every few months.

Virus Information Service
Members of the MIT community can subscribe to a virus information 
service, MITVIRUS, to get alerts and notification of new releases of 
anti-virus software. To subscribe, send email to 
<listserv@mitvma.mit.edu>. In the body of the message type

subscribe mitvirus [your real name]

If you have questions about computer viruses or anti-virus software, 
contact Jerry Isaacson of the ISO at x3-1440 or <gii@mit.edu>.