Dec 15, 2010 13:58 GMT  ·  By

New scams spotted on Facebook are tricking users into taking surveys and giving rogue apps access to their profiles, by promising them free credits in return.

There are several such scams circulating around and directing users to different pages that have the same goal of generating cost per action (CPA) income.

A message seen by researchers from Sophos reads "One time offer ! Win FREE 150 FB credits for your top games NOW! limited copies left! : http://apps.facebook.com/[censored]/"

The link takes users to a page claiming they won a Facebook credits gift card as part of a campaign run by Best Buy, Walmart and Target.

Facebook credits are virtual currency that can be spent in games or other applications on the social networking website. They can be bought in stores like the aforementioned ones.

When users try to claim the free gift card as instructed, they are prompted to allow an app called "WIN 150 CREDITS FOR GAMES" to post on their walls, manage their pages and access their profile data.

Users who fall for the trick and agree to this will unknowingly start sending spam and will be told they need to complete a "100% free offer" in order to get the credits.

As past scams have shown, these offers are never 100% free and can actually end up costing users a lot of money.

A second campaign was spotted by Facecrooks and produces messages that read "Win 900 Fb Credits for Any Game!(Limited Time Offer Gift)"

This scam, however, is less complex and asks users to manually spam their friends and paste rogue JavaScript code into their browser's address bar.

"If you've been hit by a scam like this, remove references to it from your newsfeed, and revoke the right of rogue applications to access your profile via Account/ Privacy Settings/ Applications and Websites," advises Graham Cluley, senior technology consultant at Sophos.