"The Captcha Trojan disguises itself as a stripper game that offers voyeurs the chance to see images of a model getting undressed. In order to get "Melissa" to lose an item of clothing, the user must identify the letters or numbers found within a scrambled text image that forms the basis of a captcha (Completely Automated Public Turing test to tell Computers and Humans Apart). Providing users identify the letters correctly, Melissa shows a bit more skin."

So by deciphering the text, voyeurs are unwittingly helping crooks get around checks designed to stop them establishing accounts. These newly-created accounts may later be used to send junk mail or other malign purposes.

Captchas have been used to defeat automatic sign-ups to email accounts by services including Yahoo! Mail and GMail for years. Increasingly hackers have had more success at defeating the approach. For example, the HotLan Trojan has created more than 500,000 spam email accounts with Hotmail, Yahoo! and GMail since its arrival back in July."

Link to this Story: Website CAPTCHA only as good as the porn offered to break it