New strain of Sobig virus circulating
Antivirus companies warned Tuesday that a new version of the Sobig virus is rapidly spreading on the Internet, the latest in a string of Sobig computer worms to be released. The new worm, W32.Sobig.F, first appeared on Tuesday, prompting antivirus software companies to release updated virus identity files to detect and stop the new threat.
F-Secure Corp. of Helsinki rated Sobig.F a "Level 2 Alert," indicating a large number of infections. Sophos said that it had received "many reports" of the latest Sobig worm from customers.
The first Sobig worm appeared in January, infecting machines running Microsoft's Windows operating system.
Like that worm, Sobig.F spreads through infected e-mail message attachments and unprotected shared folders on computer networks, modifying a computer's operating system so that the Sobig.F worm code is run whenever Windows is started, antivirus companies said.
When opened, the worm places a copy of itself into the Windows folder on the infected machine, creates a process to run the worm program and modifies the Windows registry so that the worm program will be launched whenever Windows is started.
