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New Facebook Attack Aims to Infect PCs with Dorkbot Worm

Facebook Attack Attempts to Infect PCs with the Dorkbot Worm Through the Social Network’s Chat System. 

A new Facebook worm has its eyes on Windows PCs.

This time, the idea is to infect users with the Dorkbot worm. Often spread via instant messaging, removable drives and compromised Websites, the Dorkbot worm opens a backdoor and allows remote access to an infected computer.

The Facebook attack appears to be spreading through the social network’s chat system. According to Sophos, a message that appears to come from a Facebook friend will include a link that may at first glance claim to point to Facebook.com, but in reality goes to a malicious site.

“Although an unsuspecting user may believe that they are clicking on a link to a JPG image, the truth is that they are downloading an executable file that attempts to download further code (another piece of malware) from the net and drops a .BAT batch file onto infected computers,” blogged Graham Cluley , senior technology consultant at Sophos. “The ultimate aim of all this malicious activity is to install the Dorkbot malware onto your Windows computer.”

Dorkbot has been known to spread via a variety of different social networks and instant chat systems in the past, Cluley told SecurityWeek. “Looks like the bad guys are using a variety of downloaders to initiate the attack on victims' computers, before ultimately taking them to Dorkbot,” he said.

Last week, security researchers discovered a separate worm on Facebook was infecting users with the notorious Zeus Trojan. In that case, the worm spread by sending direct messages that contained links to a screensaver of two women. If the user opened the screensaver, they would be hit with a flood of malware, including Zeus.

In response to the latest issue, Facebook spokesperson Frederic Wolens told SecurityWeek the company has numerous defenses in place to combat phishing and malware.

“We have internal systems in place configured specifically to monitor for variations of the spam and are working with others across the industry to pursue both technical and legal avenues to fight the bug,” he said. “Additionally, we are in the process of making changes to our Scan-and-Repair McAfee tool to help remove Dorkbot and its variants for users we have check-pointed.”

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