Miscreants have unleashed a new type of clickjacking worm onto Facebook.
The latest assault relies on tricking users into using the Facebook "Share" feature without notifying surfers that content is being shared. By contrast, an otherwise similar clickjacking attack dating back from May relied on duping a user into injudicious use of the social network's "Like" feature.
Sophos explains that the opening move for the latest attack poses as a "Facebook fan page" for the “Top 10 Funny T-Shirt Fails ROFL” and other potentially eye-catching content. These fan pages, once selected, load malicious script from an external domain that means the user will unwittingly share the dodgy page on their profile, promoting the scam to a mark's friends and contacts on Facebook.
Prospective marks running the NoScript Firefox plug-in are protected from the line of attack, which continues with a supposed "human verification step". Marks are invited to complete a time-wasting survey before they are allowed to view the T-shirts.
The shifty sorts behind the scam earn money from completed surveys from dodgy marketing outfits at the expense of wasting everyone's time and polluting Facebook with crud.
Sophos reports that the problem is even worse than that because marks taken in by the scam are invited to submit their mobile phone number, which is enrolled onto an auto renewing subscription service that costs $5 per week. Details of the terms and conditions of enrolment onto the Awesome Test are, predictably, buried in the small print.
Facebook responded promptly to the appearance of the threat by deleting fan pages associated with the scam. Meanwhile Sophos has blocked the domain hosting the malicious code, a move other security firms are likely to follow.
A full write-up of the scam, complete with screenshots, by Sophos researcher Onur Komili is here. ®