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Rumble in the Tumblr: Troll-worm infected thousands of blogs

Infamous crew unleashed JavaScript nasty on trendy journals

A worm spread like wildfire across Tumblr on Monday, defacing pages on the blogging website with an abusive message penned by a notorious trolling crew.

The outbreak was triggered by the GNAA, a group of anonymous troublemakers who get their kicks from winding up bloggers with offensive posts.

Tumblr temporarily halted the publication of new journal posts to prevent the worm from spreading further before restoring the service to normal a few hours later.

"Tumblr engineers have resolved the issue of the viral post attack that affected a few thousand Tumblr blogs. Thanks for your patience," the website's operators said in an official status update.

Net security firm Sophos reckoned the worm spread after attackers managed to embed malicious JavaScript in a Tumblr post. Anyone who viewed the booby-trapped page while logged into Tumblr spread the infectious post to their own blog, Sophos explained.

"It appears that the worm took advantage of Tumblr's reblogging feature, meaning that anyone who was logged into Tumblr would automatically reblog the infectious post if they visited one of the offending pages," wrote Graham Cluley, senior technology consultant at Sophos.

"It shouldn't have been possible for someone to post such malicious JavaScript into a Tumblr post - our assumption is that the attackers managed to skirt around Tumblr's defences by disguising their code through Base 64 encoding and embedding it in a data URI," he added.

GNAA has trolled several prominent websites including Slashdot, Wikipedia, CNN and Barack Obama's campaign site. The group founded Goatse Security, a grey-hat information security crew that infamously obtained and leaked the email addresses of approximately 120,000 early adopter Apple iPad users. Andrew "weev" Auernheimer, 27, of New York, was found guilty at the end of last month of one count of identity fraud and one count of conspiracy to access a computer without authorisation over the iPad leak incident - a court verdict condemned by many members of the information security community. ®

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