Two-wave Bagle Trojan attack launched

A spammer has struck with two waves of the BagleDL-U Trojan

Two waves of spam were launched this week using a new variant of the Bagle Trojan, according to antivirus company Sophos.

The BagleDL-U trojan tries to turn off antivirus and security software and block access to security Web sites, in an attempt to strip away a PC's immune system and allow hackers to gain access, Sophos said in a statement.

The two series of attacks bore strong similarities: the subject line was blank, the body message text was 'new price', and the malicious file attached could be identified with names such as '', '', and ''.

"All computer users must avoid opening unsolicited email attachments, and ensure that their antivirus protection is up-to-date. Businesses should also consider blocking all executable code from entering their networks via email — most companies have no need to receive computer programs via this route, and it dramatically reduces the risk of infection," said Carole Theriault, senior security consultant at Sophos.