A new variant of the Ramnit worm has managed to steal log-in credentials for several thousand Facebook accounts, most of which were from the United Kingdom and France, according to researchers at Seculert. Evidence recovered from a command-and-control server used to coordinate the evolving Ramnit worm confirms that the malware has already stolen 45,000 Facebook passwords and associated email addresses.
Discovered in April 2010, the Microsoft Malware Protection Center (MMPC) described Ramnit as “a multi-component malware family which infects Windows executable as well as HTML files”, “stealing sensitive information such as stored FTP credentials and browser cookies”. In July 2011 a Symantec report [PDF] estimated that Ramnit worm variants accounted for 17.3 percent of all new malicious software infections.
Trusteer previously reported in August of last year Ramnit gained the ability to “bypass two-factor authentication and transaction signing systems, gain remote access to financial institutions, compromise online banking sessions and penetrate several corporate networks.” Seculert, using Sinkhole, found that 800,000 machines had been infected with the worm in the last quarter of 2011.
It was fairly straightforward to detect that over 45,000 Facebook login credentials have been stolen worldwide, mostly from users in the United Kingdom and France. In a statement, Facebook said it was applying security measures to contain the problem.
“Last week we received from external security researchers a set of user credentials that had been harvested by a piece of malware. Our security experts have reviewed the data, and while the majority of the information was out-of-date, we have initiated remedial steps for all affected users to ensure the security of their accounts. Thus far, we have not seen the virus propagating on Facebook itself, but have begun working with our external partners to add protections to our anti-virus systems to help users secure their devices. People can protect themselves by never clicking on strange links and reporting any suspicious activity they encounter on Facebook. We encourage our users to become fans of the Facebook Security Page (www.facebook.com/security) for additional security information.”
As ever, be careful what you click on in Facebook, even if the link is provided by a friend and and try not to use the same password for multiple services.