By proactively using large-scale Internet enumeration, law enforcement and security teams may be able to stop operators of remote access Trojans (RATs) like DarkComet, Poison Ivy, Havex, and AlienSpy before they even launch their attack campaigns, according to a new report by Recorded Future.
The kind of data RATs often deal with require a lot of bandwidth -- photos, audio recordings, video from Webcams, etc. -- and therefore, RAT controllers are generally less tolerant of latency, according to Levi Gundert, author of Recorded Future's report. Since they're less tolerant of latency, they're less likely to operate through proxies, so compared to other kinds of malware, there are a disproportionate number of RATs that are run from residential ISP subnets.
As Gundert explains, starting from a data point like this makes attribution quicker and easier. It may make it possible for law enforcement to cut off RAT attacks before operators use the information they've collected for further nefarious aims, like blackmail or silencing political dissidents, he says.
Using this technique, Gundert says it was very easy for Record Future to attribute RAT operations to Oxford, U.K. resident Daniel James Brown (and find his street address, blood type, and the name of his dog), for instance. Other organizations were similarly able to point to RAT specific operators by username and/or location.
Shodan typically identifies between 400 and 600 individual RAT clients on any day, according to the Recorded Future report. A recent data set pulled from Shodan was overwhelmingly dominated by Dark Comet, followed by XtremeRAT, njRAT, and Net Bus. Poison Ivy and BlackShades barely made the list.
Although some RATs are created for use by nation-states and others for use by individual criminals, "threat actors continue to leverate commodity RATs even after the original author has been apprehended," because they're easy to configure, highly reusable, and proven to be effective against anti-virus, according to the report.
"They're all open-source to some degree," says Gundert. "They've all been co-opted to some degree."
Although njRAT and Xtreme RAT are used almost exclusively in the Middle East, he says, most RATs have been used "by kids to spy on females," he says.
And even after the major BlackShades sting in May 2014 where 90 people were arrested, Blackshades is still limping along: Gundert says he knows of two controllers in Turkey.