Holiday e-mails can carry virus danger.

The holiday season is often a time when computer users pass around amusing electronic animations via e-mail. Although most of these attachments are harmless, some may hide destructive computer viruses. Indeed, anti-virus watchdogs identified a new virus this week that masquerades as an innocuous bunch of digital photos but actually plants a time bomb that will erase the computer_s hard drive on Jan. 1, 2000. Because that_s the same date that the Y2K bug is expected to cause many computer systems to crash, the virus might fool users into believing they have a Y2K problem. Virus fighters expect more viruses linked to Y2K to emerge as Jan. 1 approaches, and they are once again begging computer users to avoid opening e-mailed attachments. ``We_re telling people to be very wary of electronic Christmas cards,'' said Sal Viveros, a virus expert with Network Associates Inc., based in Santa Clara. The Mypics worm, as this latest threat is called, arrives attached to what appears to be e-mail from a friend or associate that says, ``Here_s some pictures for you!'' Opening the attached file, Pics4You.exe, will infect your computer with the virus, which will attempt to mail itself to 50 people it finds in your Microsoft Outlook e-mail address book. It will also change the home page of your Microsoft Internet Explorer Web browser to a pornographic site. The real damage occurs Jan. 1, when the virus will change the computer_s most basic software and attempt to erase the hard drive. The increasing frequency of alerts relating to things like electronic viruses is prompting renewed calls for safe computing, but few experts expect users to change their habits. ``It would be great if everybody followed the rule: Never open e-mail attachments if you can help it,'' said Carey Nachenberg, chief researcher at Symantec_s anti-viral research center. In general, just looking at an infected e-mail can_t hurt; users have to do something else to activate the virus and infect their system. Typically, a virus comes as an attachment to e-mail, such as a document that can be read only with a word processor like Microsoft Word. Until recently, experts advised users to simply avoid opening attachments sent by people they didn_t know. Unfortunately, the most troublesome viruses today spread by fooling people into believing the document was sent by a friend. For instance, Mypics attempts to mail copies of itself to anyone in the user_s e-mail address book. Anyone receiving such a missive from, say, their brother, might open that attachment without thinking about it. Most software vendors are aware of the problem and take steps to get around it.