New Bagle-B worm spreading, warns Sophos

February 17, 2004 Sophos Press Release

Sophos, a world leader in protecting businesses against spam and viruses, is warning of a new worm called Tanx-A (also known as Bagle-B). Sophos has received several reports of this worm spreading in the wild.

The Tanx-A (Bagle-B) worm spreads via email and arrives with the subject line 'ID' followed by various random characters and the message text 'Yours ID'. An attached .exe file, has a randomly generated filename. If run, a remote access component allows hackers to gain remote access to infected computers.

The worm harvests email addresses from infected PCs and, when forwarding itself on to other computer users, spoofs the "From:" field using addresses found on the computer's hard drive.

"Bagle-B tries to deceive computer users by spoofing the sender's address, but the worm is easy to spot because of its distinctive subject line," said Carole Theriault, security consultant, Sophos. "The message is simple - don't open unsolicited emails and don't automatically trust emails that appear to come from a known contact. Practising safe computing and blocking executable files at the email gateway will prevent infection from this worm."

Like its predecessor, Bagle-A, this worm has a built in 'dead date' and has been designed to fall dormant on 25 February 2004.