The scam claimed to offer a tool to find out the Facebook passwords of friends, but instead compromised the user’s account by tricking them into using some code that takes control of their account and exposes their friends’ data in the process.
“What really happens when you paste this code into your browser console window is that a series of actions are performed using your Facebook account without your knowledge.
"Behind the scenes, your account is used to follow lists and users, and give likes to pages in order to inflate the follower and like counts defined by the scammers,” explained Satnam Narang, a security response manager for Symantec in a blog post.
The scam employs an instructional video explaining “Facebook Hacking”, which linked to a Google document that contains some code.
The code allows users to see friends’ Facebook passwords, according to the scammers, with the instructions attempting to convince users to paste the code into their browser console window – a feature of most browsers that allows developers to inspect and modify elements of a website and how it is presented in the browser.
The instructions explain that the code will take two hours to work, belaying immediate suspicion when nothing happens to reveal the passwords of their friends.
In reality the code performs actions behind the scenes using the would-be hacker’s Facebook account, including following certain users and liking pages. No doubt the scammers are being paid to artificially inflate the follower or like counts of some users and pages.
'Playing off the curiosity of your friends'
The code also attempts to attract new targets through social engineering on Facebook.
“Your account is also used to tag the names of all your friends in the comment section of the original post. This is done to help the scam spread further, playing off the curiosity of your friends, who may visit the post to find out more and hopefully follow the instructions as well,” explains Narang.
The scam uses a variation of what is called self cross-site scripting (self-XSS), where a user is tricked into entering code into their browser’s console window that performs certain actions on their behalf.
“The code usually posts the same scam on other people's walls, and subscribes the user to pages controlled by the attacker – but it could do much worse things. To avoid this, the console is now gently disabled in some browsers,” Facebook continues.
'If it sounds too good to be true…'
This type of scam is not new, and was first seen circulating around Facebook in 2011. This scam variant was first seen at the beginning of the year, modified from the original code that saw great success with between 50,000 to 100,000 users falling victim.
The new scam originates from India, according to Symantec, based by the locations of pages and profiles users are tricked into liking as part of the scam.
Users who have been affected by the scam should use their activity log on Facebook to track the errant likes and friending, removing those that the scam artificially created and any post that could spread the scam further.
“Always remember that if it sounds too good to be true, it is. Being able to hack someone’s Facebook password by just pasting some code into your browser sounds way too easy and should signal that this is a scam,” concludes Narang.
• Facebook’s F8 conference: what do regular Facebook users need to know about the social network’s biggest event
guardian.co.uk © Guardian News and Media Limited 2010