The attack abuses Twitter trending topics -- a popular source of abuse -- but with a twist: Rather than installing fake antivirus software like most similar attacks, it installs a new banking Trojan that steals online banking accounts, credit card PIN numbers, and online payment system passwords, according to Kaspersky Lab.
Dmitry Bestuzhev, senior antivirus researcher at Kaspersky Lab, says the attack injects malicious tweets from the attackers' own malicious Twitter profiles. Tweets include the words "Official Twitter App," which was No. 7 of the Top 10 trending topics on Twitter. In one case, the tweet includes a link to a "video" purportedly of the Olympic mascot. "I saw a lot of people retweeting this news several times without even checking the source," Bestuzhev says. "The victims who clicked on the links were forced to open a Web page with a malicious Java archive file on it. This one downloaded and installed the Trojan banker to the victim machine."
The aggressive Trojan also disables Windows Task Manager, regedit, and notifications from Windows Security Center as a way to avoid detection. "From the moment the malicious code was active and running, if the victims opened their online bank account, made an online payment with a credit card, or by PayPal, eBay, or any other online payment system, all sensitive information was stolen and sent as encrypted information to the criminals," Bestuzhev says. The Trojan can also spread via USB devices.
Kaspersky Lab discovered the Trojan worm copies itself onto the infected system with the name "Live Messenger," and it can check whether the hard drive is virtualized. If it is, the malware won't run. The anti-malware firm calls the Trojan "Worm.Win32.VBNA.b."
Researchers at PandaLabs also have spotted the Trojan attack and blogged about it here.
Interestingly, while the attackers have the ability to take over an infected Twitter account and send malicious tweets to the victim's followers, so far they don't appear to be doing so. "They just used several recently created Twitter accounts with few followers," Bestuzhev says. But they have the capability to steal the victims' Twitter account credentials, as well, with this attack, he says.
So who's behind the attack? Bestuzhev says it appears to be coming out of Latin America -- namely, Brazil -- unlike many of the rogue AV campaigns, which typically originate in Russian-speaking countries. He posted a blog on the attack here yesterday.
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