Sophos said that the new Sober variant was the fifth most reported virus over the last 24 hours, closely followed by versions of Zafi and Netsky. It's thought that all the major antivirus companies are now offering protection against the worm, so users should update their virus protection.
Sober.M is a mass e-mailing virus that spreads as a .zip file attachment and affects systems running Microsoft Windows. The e-mail containing the worm sends itself in German or English language.
Once again, we recommend that you do not download attachments from untrusted sources. Keep your machine up to date with the latest virus definitions and patches for the OS. Use a firewall, and if you don't think an e-mail comes from someone you expected mail from, then delete it.