The worm, a virus that propagates itself to other computers through the Internet or other networks, is affecting users of Microsoft Corp.'s Outlook and Outlook Express, said Ian Hameroff, business manager of security solutions at Computer Associates International Inc.
The e-mail has a subject line of "Hi," and asks the user to check a screen saver program, which is attached. If the recipient runs the screen saver, the computer becomes infected. Like many e-mail attacks, it sends itself out to everyone in the victim's address book.
People using ICQ instant messenger and Internet Relay Chat also are susceptible to the worm because files can be transferred across those networks, Hameroff said.
Researchers estimated thousands of computers had been infected by the worm, which is believed to have originated in France, according to April Goostree, virus research manager at McAfee.com.
"This is at outbreak status, which is very rare," Goostree said. "The last outbreak we had was 'Love Letter' in May 2000."
A virus is given outbreak status by McAfee.com if it is determined to be spreading quickly and affecting large corporate networks as well as individual computer users, Goostree said.
Computer experts advise that people not open unexpected e-mail attachments, even if the sender is someone familiar. Computer users should update their anti-virus software at least weekly.
Goner also attempts to delete critical files for any security or anti-virus program the victim might have installed.
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