Written by Kevin Poulsen / Courtesy of Wired.com


Feds Are Suspects in New Malware That Attacks Tor Anonymity

Security researchers tonight are poring over a piece of malicious software that takes advantage of a Firefox security vulnerability to identify some users of the privacy-protecting Tor anonymity network.

The malware showed up Sunday morning on multiple websites hosted by the anonymous hosting company Freedom Hosting. That would normally be considered a blatantly criminal “drive-by” hack attack, but nobody’s calling in the FBI this time. The FBI is the prime suspect.

“It just sends identifying information to some IP in Reston, Virginia,” says reverse-engineer Vlad Tsyrklevich. “It’s pretty clear that it’s FBI or it’s some other law enforcement agency that’s U.S.-based.”

If Tsrklevich and other researchers are right, the code is likely the first sample captured in the wild of the FBI’s “computer and internet protocol address verifier,” or CIPAV, the law enforcement spyware first reported by WIRED in 2007.

Court documents and FBI files released under the FOIA have described the CIPAV as software the FBI can deliver through a browser exploit to gather information from the target’s machine and send it to an FBI server in Virginia. The FBI has been using the CIPAV since 2002 against hackers, online sexual predators, extortionists, and others, primarily to identify suspects who are disguising their location using proxy servers or anonymity services, like Tor.

The code has been used sparingly in the past, which kept it from leaking out and being analyzed or added to anti-virus databases.

The broad Freedom Hosting deployment of the malware coincides with the arrest of Eric Eoin Marques in Ireland on Thursday on an U.S. extradition request. The Irish Independent reports that Marques is wanted for distributing child pornography in a federal case filed in Maryland, and quotes an FBI special agent describing Marques as “the largest facilitator of child porn on the planet.”

Freedom Hosting has long been notorious for allowing child porn to live on its servers. In 2011, the hactivist collective Anonymous singled out Freedom Hosting for denial-of-service attacks after allegedly finding the firm hosted 95 percent of the child porn hidden services on the Tor network.

Freedom Hosting is a provider of turnkey “Tor hidden service” sites — special sites, with addresses ending in .onion — that hide their geographic location behind layers of routing, and can be reached only over the Tor anonymity network.

Tor hidden services are ideal for websites that need to evade surveillance or protect users’ privacy to an extraordinary degree – which can include human rights groups and journalists. But it also naturally appeals to serious criminal elements.

Shortly after Marques’ arrest last week, all of the hidden service sites hosted by Freedom Hosting began displaying a “Down for Maintenance” message. That included websites that had nothing to do with child pornography, such as the secure email provider TorMail.

Some visitors looking at the source code of the maintenance page realized that it included a hidden iframe tag that loaded a mysterious clump of Javascript code from a Verizon Business internet address located in Virginia.

Continue Reading over at Wired.com.