An email-borne virus that apparently originated in Germany is in the wild but has not yet spread widely or affected many users, according to an antivirus researcher.
The worm-type virus, called W32/Sober@MM, or Sober, is being spread as an attachment to a variety of email messages written in either English or German, a virus research engineer at McAfee Security, Craig Schmugar, said.
Some of those email messages identified the attachment as an update to Kaspersky Labs or Symantec Norton AntiVirus software, he said.
McAfee classified the virus as "low-profiled". 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 email address for reporting of viruses, Schmugar said.
They had not been sent in by customers who had been hit by it, he said. The spread had so far been fairly restricted to Germany.
The worm is designed to propagate itself by emailing itself to addresses extracted from the victim's machine. It did this using its own Simple Mail Transfer Protocol (SMTP) engine and a variety of subject lines, messages and attachment names in the messages, McAfee said.
To foil users who tried 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 email 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 antivirus companies should be updating their antivirus signatures soon to detect and remove the worm, he said.