From PC Magazine
Facebook Worm Sells Itself with a Booty Call
Gadi Evron noted a new Facebook worm over the weekend. The hook to it appears in a friend’s profile as the racy image at left.
Click the image, and you are brought to a Web page with the same image.
Analysis by famous malware analyst Nick Fitzgerald calls this a CSRF
(Cross-Site Request Forgery) attack, a cousin to cross-site scripting:
A sequence of iframes on the exploit page call
a sequence of other pages and scripts, eventually resulting in a form submission to Facebook “as if” the victim had submitted a URL for a wall post and clicked on the “Share” button to confirm the post.
Afterward, you are redirected to a porn site.