Bagle Virus is morphing quickly

A new variant of the Bagle downloader virus is spreading havoc again on unsuspecting users´ machines. The malware, believed to have originated from a Yahoo news group, directs infected computers to download Trojans and turns PCs into a zombie network able to be controlled and sold for use by hackers.

Approximately 80 variants of the original Bagle worm, which first appeared in January 2004, have been released on the Internet. The first Bagle downloader variant MessageLabs tracked drops a Trojan horse that attempts to download Bagle from a list of about 130 websites worldwide.

Experts warn that the Trojan is triggered by opening the file, which arrives as an e-mail attachment. It is then installed and checks a list of Web sites for updates and other files that it can download and execute.

The Trojan also updates itself to run other malware on the infected machine, depending on the files it finds on the sites it checks, the firm said. The downloader also disables virus-protection programs and forwards itself to E-mail addresses stored on the victim´s computer.