A Helsinki, Finland-based data security company is warning Netizens about a computer worm, called Happy99, that can send hundreds of copies of itself to the same newsgroups and e-mail addresses to which an infected user is posting or e-mailing.
According to Data Fellows Inc, users' PCs don't suffer ill effects by reading a Happy99 message in a Usenet newsgroup or in e-mail. When someone executes the Happy99.exe attachment, a fireworks display appears on the screen. Meanwhile, in the background, the worm alters the host computer's Internet configuration to keep track of all e-mail or newsgroup activity.
The worm then spams itself to the same newsgroups and e-mail addresses to which a user posts. It also maintains a list of newsgroups to which it has sent a copy of itself.
Data Fellows said the worm doesn't pose a threat to computer files in the way a virus would but warned that it could slow down or crash corporate e-mail servers because of the volume of messages involved.
Original PC configurations can be restored by renaming the host computer's winsock32.dll file. In addition, Data Fellows has a patch available on its Web site at http://www.datafellows.com/