New Variant Of Bagle Virus Spreading Fast

A new variant of the Bagle downloader virus is on the loose, according to E-mail security company MessageLabs Ltd. The company says the malware appears to have originated from a Yahoo Groups address and claims to have blocked almost 70,000 copies of the virus in the four hours since it was detected Tuesday.

Unsuspecting computer users trigger the downloader by opening the file, which arrives as an E-mail attachment. The downloader installs a Trojan program that checks a preset list of Web sites for updates and other files that it can download and execute. The Trojan is thus able to update itself or run other malware on the infected machine, depending on the files it finds on the sites it checks. The downloader also disables virus-protection programs and forwards itself to E-mail addresses stored on the victim's computer.

F-Secure Corp., an antivirus company, rates this Bagle variant at Level 2 on a three-level scale, with Level 1 being the most severe.