Computer Associates International on Thursday warned of a new computer worm on the horizon, the "Plage2000," which could threaten computer e-mail systems as well as e-business infrastructures.

The worm has been reported to be "in the wild" by customers of Computer Associates, the company said. A worm is a computer program that replicates itself and spreads from computer to computer and infects an entire system. A computer virus spreads from file to file. A worm can spread without human intervention. The Plage2000 arrives as a reply to an e-mail previously sent by the user. The original e-mail will be quoted completely in the reply. The arriving e-mail says: P2000 Mail auto-reply: "I_ll try to reply as soon as possible. Take a look to the attachment and send me your opinion!" Get your FREE P2000 Mail now! The worm is attached to the message under one of the following names: pics.exe, images.exe, joke.exe, PsPGame.exe, newsdoc.exe, hamster.exe, tamagotxi.exe, searchURL.exe, SETUP.EXE, Card.EXE, billgt.exe, midsong.exe, s3msong.exe, docs.exe, humor.exe, or fun.exe. Every five minutes the worm tries to establish a connection to a running Outlook or Exchange client. When new e-mails are received it will reply to the unread e-mails with an e-mail like the one above. The original messages remain unread. Although the worm does not have a destructive payload, its e-mail propagation mechanism poses a threat to any eExchange e-mail infrastructure since it can overload and take down mail servers.