Cybercrooks are offering what purports to be source code for the infamous ZeuS cybercrime toolkit through underground forums.
The would-be seller, nicknamed IOO, has lent credibility to the offer by including screenshots of what appears to be portions of the source code for ZeuS to his sales pitch. IOO offers to discuss the sale to prospective buyers via either Jabber or ICQ. He is prepared to accept payment via any escrow service.
The screenshots make reference to peinfector.cpp, a project of ZeuS known as "Murofet". Security researchers - while unable to verify the sale is genuine - are taking the potential offer seriously.
"Prior to this there were several rumors that the Zeus/Zbot code was sold to the creator of SpyEye," writes Peter Kruse, an eCrime specialist who works for Danish security consultancy CSIS Security.
"This is also currently unconfirmed - however what is certain is the fact that someone besides the author of the ZeuS/Zbot has access to the code."
Whether the specific sale by IOO is genuine or not, Kruse is sure that the secret recipe of ZeuS has become accessible to more people over recent weeks. "We have also seen compile logs confirming that ZeuS/Zbot code is available to broader audiences," he told El Reg.
ZeuS is best thought of as a customisable cybercrime toolkit that makes it easy for cyber-crooks without coding skills to knock out banking Trojans. Crooks can buy licences to use the tool via underground forums in order to develop keystroke logging tools that capture bank login credentials from compromised machines before uploading the credentials where they can be recovered by crooks for subsequent misuse.
Last October the FBI announced it had broken up a major cybercrime ring that used ZeuS to steal around $70m. Around 50 alleged phishing mules in the US and the UK were named as suspects as part of this operation. More significantly five Ukrainians suspected of controlling the whole operation were cuffed. The identity of the actual creator of ZeuS remains unknown. ®