CAPTCHA Hacks
Less than two months ago, it was announced that Yahoo's CAPTCHA system was hacked by a Russian team. CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart) are verification systems that scramble text into an image indecipherable by machines. While basic CAPTCHAs have been reported hacked in the past as part of a rainbow database project, the CAPTCHAs used by the big three (Yahoo, MSN and Google) were largely considered bastions of defense against spam. The methodology employed by the Russian team yielded 35% accuracy in bypassing the Yahoo's CAPTCHA mechanism. Shortly after Yahoo fell, MSN's CAPTCHA fell (with a 1 to 3 accuracy ratio) and shortly after that, Google's CAPTCHA was compromised (with a 1 to 5 accuracy ratio) as well. The latest technique involves using a sophisticated botnet performing traffic analysis, keyboard logging and a number of tricks in order to bypass the CAPTCHA's for the purpose of creating fraudulent spam e-mail accounts.