WikiLeaks supporters are milking Twitter's application programming interface to carry out attacks that have led to crippling slowdowns at MasterCard.com, Visa.com and other websites that cut off funding to the whistle-blower outfit.
A relatively new Java-based version of the Low Orbit Ion Cannon, which protesters use to direct torrents of traffic at sites they disapprove of, allows users to specify a Master Twitter ID, according to a Thursday post on the Sans blog. It's the first time the point-and-click attack tool has included the Twitter field, security researchers said.
“The Twitter angle in this application piqued my interest,” Sans handler on Duty, Mark Hofman, wrote. “It is using the Twitter API in a new and creative way, certainly one that hadn't readily occurred to me.”
He didn't say exactly what JavaLOIC did with Twitter's API, but Jose Nazario, senior manager of security research at Arbor Networks, speculated it probably coordinated the timing and targets of attacks. If so, it wouldn't be the first time Twitter has been used as a command and control channel for corralling large networks of PCs. There are even tools available to streamline the configuration of Twitter-based C&Cs.
Sophos has more more additional details about LOIC, including its Twitter feature, here.
Other versions of LOIC use internet relay chat channels to coordinate attacks. Volunteers install the program and then enter the address of an IRC server. From there, organizers are able to instruct thousands of machines to march in lock step as they attack websites. The ability to turn on and off huge amounts of traffic quickly makes the attacks much harder to defend against.
Sean-Paul Correll, a threat researcher with Panda Security, said at the height of the attacks on Wednesday, there were more there 3,000 machines participating in LOIC-based attacks against MasterCard, Visa, PayPal and other sites that cut off services used to fund WikiLeaks. He also observed independent botnets with as many as 30,000 compromised computers also participating in the attacks.
The attacks have wreaked a fair amount of damage. By Correll's estimate, MasterCard has suffered more than 32 hours of downtime since Tuesday, with 23 of those hours being almost continuous. Parts of Visa's site saw more than 21 hours of downtime. The most crippling attack on Visa started a little before 1pm California time on Wednesday, when organizers transmitted a command over IRC to flood the site with more traffic than it could handle.
“It was down instantly,” he told The Register. “As soon as they started pointing the servers over to it, it was toast.”
Visa and MasterCard representatives have said no customer data has been accessed as a result of the attacks, and transactions have been able to go normally. Still, it was widely reported that MasterCard's Securecode service for secure online transactions was offline for much of Wednesday.
Nazario said as the attacks have progressed many have begun attacking targets' backend servers, where damage is often more severe despite it being less obvious to outside observers.
“If you can't load the Visa homepage, so what,” he explained. “But if the backend for some of these sites is down, where it integrates with other vendors or other sites, then they have a problem. That's what [the attackers] seem to be trying to do now as a way of shutting down their ability to take and make payments.”
WikiLeaks sympathizers aren't the only ones getting into the denial-of-service game. Anonops.net, a site used to by organizers of the attacks, was itself taken down on Wednesday night, Correll said. At time of writing, it was inaccessible. ®