Recognizing When You Don't Have A Virus - McAfee VIRUSSCAN 4.5 Administrator's Manual

Removing Infections From Your System

Recognizing when you don't have a virus

Personal computers have evolved, in their short life span, into highly complex
machines that run ever-more-complicated software. Even the most farsighted
of the early PC advocates could never have imagined the tasks for which
workers, scientists and others have harnessed the modern PC's speed,
flexibility and power. But that power comes with a price: hardware and
software conflicts abound, applications and operating systems crash, and
hundreds of other problems can crop up in unlikely places. In some cases,
these failures can resemble the sorts of effects that you see when you have a
virus infection with a destructive payload. Other computer failures seem to
defy explanation or diagnosis, so frustrated users blame virus infections,
perhaps as a last resort.
Because viruses do leave traces, however, you can usually eliminate a virus
infection as a possible cause for computer failure relatively quickly and easily.
Running a full VirusScan scan operation will uncover all of the known virus
variants that can infect your computer, and quite a few of those that have no
known name or defined behavior. Although that doesn't give you much help
when your problem really results from an interrupt conflict, it does allow you
to eliminate one possible cause. With that knowledge, you can then go on to
troubleshoot your system with a full-featured system diagnosis utility.
More serious is the confusion that results from virus-like programs, virus
hoaxes, and real security breaches. Anti-virus software simply cannot detect
or respond to such destructive agents as Trojan horse programs that have
never appeared previously, or the perception that a virus exists where none in
fact does.
The best way to determine whether your computer failure resulted from a
virus attack is to run a complete scan operation, then pay attention to the
results. If the VirusScan application does not report a virus infection, the
chances that your problem results from one are slight—look to other causes for
the symptoms you see. Furthermore, in the very rare event that the VirusScan
application does miss a macro virus or another virus type that has in fact
infected your system, the chances are relatively small that serious failures will
follow in its wake. You can, however, rely on McAfee researchers to identify
and isolate the virus, then to update VirusScan software immediately so that
you can detect and, if possible, remove the virus when you next encounter it.
To learn how you can help the virus researchers help you, see "Reporting new
items for anti-virus data file updates" on page xvii.
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