Web site operators and people who run computer systems will be watching for more than the Y2K bug on New Year's Eve: They will be on guard for viruses and other mischief spread by hackers looking for some start-of-the-millennium attention.
The threat has prompted several Web site operators to shut down beginning Friday. For some companies, security breaches could cause greater problems than year 2000 glitches.
"We are anticipating that there will be some increase," said Kathy Fithen, manager of a group that monitors online security threats at Carnegie Mellon University in Pittsburgh. "We are anticipating some of the intruders will try to masquerade the attack as a Y2K failure."
At least three viruses are timed to hit Saturday and could delete files on infected computers. Five other viruses that struck earlier pretended to be Y2K fixes or New Year's greetings. Anti-virus companies have distributed software updates to kill those viruses, but new forms of attack are possible.