"Anonymous supporters have been deceived into installing Zeus botnet clients purportedly for the purpose of DoS attacks. The Zeus client does perform DoS attacks, but it doesn't stop there. It also steals the users' online banking credentials, webmail credentials, and cookies," according to a Symantec Security Response blog posted Sunday.
Symantec said it had traced related attacks back to January 20, 2012, which is the day that the FBI took down Megaupload. "An attacker took a popular PasteBin guide, used by Anonymous members for downloading and using the DoS tool Slowloris, and modified it," said Symantec. As of February 15, 2012, Symantec said that 470 Tweets still linked to the Pastebin post with the malicious link.
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According to a site devoted to Slowloris, the DDoS tool "holds connections open by sending partial HTTP requests." But the Pastebin post--the original dates from May 2011--was modified to include a link to a Trojanized version of Slowloris. "When the Trojanized Slowloris tool is downloaded and executed by an Anonymous supporter, a Zeus (also known as Zbot) botnet client is installed," said Symantec. "After installation of the Zeus botnet client, the malware dropper attempts to conceal the infection by replacing itself with the real Slowloris DoS tool."
Zeus malware is designed to steal people's sensitive financial information, but is also often used by attackers to surreptitiously turn infected PCs--aka zombies--into nodes in a botnet. In other words, Anonymous attackers who download the malicious version of Slowloris could find their PCs participating in a DDoS attack, just not of their own choosing.
That's in addition to this implementation of Zeus being used, said Symantec, to transmit "cookies, online banking credentials, and webmail credentials" from an infected PC to the botnet owner's command-and-control server.
While Anonymous has generally expressed antagonism toward security firms--the hacktivist collective did create a spin-off dubbed AntiSec, after all--The Register spotted at least one pro-Anonymous Twitter channel picking up on Symantec's Slowloris malware warning, in a post that read, "Anonymous supporters tricked into installing Zeus trojan. This MUSTN'T happen. Be careful what you post and click on!"
This isn't the first warning related to the tools offered for participating in Anonymous DDoS campaigns. Last year, for example, LulzSec leader Sabu labeled the group's low orbit ion canon DDoS tool as a joke. What's curious with the malicious version of Slowloris discovered by Symantec, however, is that beyond stealing the financial details of whoever installs it, the software also still attacks websites targeted by Anonymous.
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