There are increasing reports of Y2K related viruses and other malicious code. These can be viruses which masquerade as Y2K fixes or tools, Viruses which mimic Y2K problems to avoid immediate detection, or viruses which have January 1, 2000 as the "payload trigger date." For more information and identification of specific known threats, see:

Symantec's AntiVirus Research Center

McAfee's W32/ExploreZip.worm.pak Help Center

McAfee's W95/Babylonia Help Center

A good writeup on Y2K Viruses from James Madison University

The Y2K Project Office strongly urges all users to keep anti-virus software updated frequently, since all vendors of AVS are updating for these new viruses as soon as they are identified.