Handle a Virus In Your System

So you think you've got a virus. Maybe you have, maybe you haven't. This is to help you decide. A lot of people may have problems with their computers and problems related to hardware, software or user error, are often attributed to viruses.

Rule #1 - Don't Panic

First of all, why do you think you have a virus? Is it because an anti-virus package told you so? Like other software, anti-virus software is not infallible and some anti-virus packages give many false alarms. Here are some indicators that it might be a false alarm:

• Only one file is infected on your hard disk (viruses are designed to spread, so a single infected file is unusual).
• The virus being reported is one of the several thousand that are not known to be "in the wild"
• The anti-virus package doesn't name the virus that it thinks you have
• Your anti-virus says it has found "traces in memory" of the virus, yet when you do a scan after clean-booting, it finds nothing.

Here are some indicators that it might really be a virus. Remember that they are just indicators; none of them provides conclusive proof that you definitely have a virus:

• According to an anti-virus package, several files on the computer are infected, all with the same virus
• It is a virus that is known to be "in the wild"
• More than one anti-virus package agrees that you have a virus
• Several COM and/or EXE files on your computer are all larger than they used to be, by about the same amount.
• Windows 95 refuses to use 32 bit disk access, or 32 bit file access
• If you try to save a Word for Windows document (using File|Save As), the options are greyed-out. You cannot select the drive, folder or directory in which to save the file and 'Document Template is the selected option in the 'Save File as Type' box
• If your anti-virus software says that it has identified the virus, then it means that it has not just found a byte-signature, it means that it has checksummed all the constant virus bytes, and they match the checksum in it's database. So, it's very unlikely to be a false alarm.

Here are some indicators that tell you nothing about the likelihood that you have a virus (included here because many people think that they do):

• Your hard disk doesn't work any more
• You're getting unusual graphics on your screen
• Your hard disk light seems to come on for no particular reason
• You just ran some downloaded software

If this hasn't helped you work out whether you have a virus or not, the next step is to send the file to an anti-virus company for examination.