Viruses/Worms News

Bredo botnet battles Zeus for control of PCs

Monday, October 26, 2009

In the dark world of the cybercriminal economy, computer viruses battle not just against anti-virus security software, but even other strains of malware for control of infected PCs, security researchers said.

A strain of Trojan malware identified as Bredo contains code that disables the Zeus/Zbot Trojan and moves files to prevent Zeus from reinstalling itself on reboot, according to security researchers from Sophos.

Malware authors have previously targeted other malware as a way to keep PCs under their control and not controlled by a rival bot herder. The cybercriminals use networks of infected PCs - called botnets - to distribute malware and spam and for stealing user credentials, passwords and contact lists.

"These guys want to control your computer but don't like to share," Sophos said on its malware blog recently.

The Zeus botnet has been spreading its malicious payload in spam emails that spoof messages form Microsoft Outlook, the IRS and companies' own IT departments. Users who click on a link in these messages can be infected by the Trojan upon visiting a malicious website.