Sophos says beware of new Facebook "dislike" button scam. The link reads: "I just got the Dislike button, so now I can dislike all of your dumb posts lol!!"
Falling for the scam will give the rogue application permission to access the user's profile, posting spam messages from the account. Sophos's Graham Cluley goes on to explain:
the rogue application requires you to complete an online survey (which makes money for the scammers) before ultimately pointing you to a Firefox browser add-on for a Facebook dislike button developed by FaceMod.
Sophos does not believe FaceMod is connected with the scam. It's just being used as bait.