Nimda Variant Spreads Across Net

The variant of the Nimda worm discovered Tuesday had spread across much of the globe by midday Eastern time Wednesday and the worm's author is also spreading a message of his or her own in this new version, according to antivirus firm F-Secure.

Nimda.e, the new variant, is a recompiled version of the original worm that functions in the same way as the original, but has some of its files renamed. What's entirely new to this version, however, is that the author of the worm has included a message to the world, according to Fred Fondreist, director of business development at antivirus firm F-Secure.

Nimda's author has included something that reads very much like a copyright notice in the worm's code, as well as a note expressing his frustration that the worm is being called Nimda, rather than "CV" or "concept virus," the names he had intended, Fondreist said. There is an older, separate virus with the name "concept."

Patch Available

The Nimda worm first caused problems for Internet users in mid-September. Nimda spreads itself as an e-mail attachment, via server-to-server Web traffic, through shared hard disks on networks and by automatically downloading infected files to users who browse Web pages hosted on infected servers.

The worm exploits flaws in Microsoft 's Internet Explorer Web browser and in the company's Internet Information Server Web server platform. Patches for both applications are available from Microsoft.

The new worm is spreading quickly and users are urged to patch their systems and update their antivirus programs, Fondreist said. F-Secure Wednesday raised the threat level of the variant to the highest level because of how far the worm has spread, he said. Other antivirus firms have yet to raise the new Nimda above a medium-level threat, though some have it ranked even lower.

Antivirus company Trend Micro has yet to see a significant spread out the worm outside of Asia, according to David Perry, spokesperson.

"If it makes it into general circulation in the United States, it will not have the same punch as Nimda.a (the original worm)," thanks to the high number of users who have applied patches, Perry said.