Sober virus in the wild but slow-moving

An e-mail-borne virus that apparently originated in Germany is in the wild but has not yet spread widely or affected many users, an anti-virus researcher said Monday.

The worm-type virus, called W32/Sober@MM, or Sober, is being spread as an attachment to a variety of e-mail messages written in either English or German, said Craig Schmugar, a virus research engineer at McAfee Security, a division of Network Associates Inc., in Santa Clara. Some of those e-mail messages identify the attachment as an update to Kaspersky Labs or Symantec Norton AntiVirus software, he said.

McAfee classified the virus as “low profile” in the late afternoon Monday, Pacific Time. Fewer than 20 corporate customers had been affected and most copies of the virus received by McAfee had been sent by the virus itself directly to a McAfee e-mail address for reporting of viruses, Schmugar said. They had not been sent in by customers who had been hit by it. The spread had so far been fairly restricted to Germany, he said.

The worm is designed to propagate itself by e-mailing itself to addresses extracted from the victim’s machine. It does this using its own Simple Mail Transfer Protocol engine and uses a variety of subject lines, messages and attachment names in the messages, according to McAfee. To foil users who try to remove it by hand, the worm creates two copies of itself, Schmugar said.

To prevent infection, users should use standard safe computing practices such as not opening e-mail attachments they aren’t expecting even if they are from a familiar sender, he said.

Judging from its spread so far, and because in some cases it presents the recipient with a foreign-language message body, it may not have a large impact, he said.

“It’s not an unlikely guess that this might be gone in a couple of days and never really reach a high prevalence rate,” Schmugar said.

McAfee and most anti-virus companies should be updating their anti-virus signatures soon to detect and remove the worm, he said. Later Monday or on Tuesday, McAfee will have updated its stand-alone Stinger software tool, he said. More information about the worm is available here.