A computer security company on Tuesday warned Facebook users against clicking on a link claiming to be the "sexiest video ever" which is actually a trap designed to infect computers.
The firm, Sophos, said that thousands of users have been hit by the malicious post, which appears to come from a friend's Facebook account.
The posting reads: "This is without doubt the sexiest video ever!" and is accompanied by what seems to be a movie thumbnail of a woman wearing a short skirt on an exercise bike.
Sophos warned Facebook clients against clicking on the thumbnail, which does not play the video but takes users to a page telling them they do not have the correct software installed.
It then tricks users into installing adware, a software package that automatically plays, displays or downloads advertisements to their computer.
"You may want to watch a sexy video, but you're more likely to end up being plagued by pop-up advertising," said Graham Cluley, a senior technology consultant at Sophos.
"Not only is adware being installed in your computer, but the rogue Facebook application is posting the same message to all of your friends' accounts," he said.
"It's no surprise that your friends might click to watch the movie when it looks to all intents and purposes that you are the person who has sent it to them."
Cluley advised those who had been affected by this attack to scan their computers with anti-virus software, change their passwords, review their Facebook application settings and remove whatever was installed.
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