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World TOP Headlines: => Latest Security News & Alerts => Topic started by: Samker on 06. October 2008., 07:58:55

Title: Spam swine break next-gen CAPTCHAs
Post by: Samker on 06. October 2008., 07:58:55
(http://www.brainsfeed.com/uploads/google_captcha.png)

Spammers have reportedly defeated revised CAPTCHAs from both Google and Microsoft.

Worse, miscreants intent on establishing online webmail accounts to bombard us all with useless stock tips and penis pills have also broken other forms of verification system designed to tell humans and computers apart, such as kitten-based approaches to image picking posers.

Spam-tools scumbags behind the XRumer utility boast their application can defeat improved CAPTCHA controls deployed by both Hotmail and Google in response to earlier cracks, according to reports in the blogosphere.

XRumer is used for applications including littering forums with spam in a bid to increase search engine rankings. The latest version is also able to break cat-based authentication.

Credibility to these claims is lent by an analysis by a web security firm earlier this week, reporting that improved CAPTCHA-controls at Hotmail were broken by black hats.

CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart) are often used to prevents automated sign-ups to webmail accounts and the like. Punters typically have to identify letters depicted in an image, a recognition task easy for humans but tricky for computers.

Spammers are interested in defeating these protections because a webmail account is more likely to get through at least some anti-spam controls. Spam filtering firms such as MessageLabs, have responded by applying "throttling controls" after seeing an upsurge in junk mail messages originating from webmail accounts.

Originally it was thought that sophisticated automated tools alone were being used to defeat CAPTCHA controls and establish webmail accounts that might later be abused for spamming. Evidence now points to a theory that both men and machines are involved in the process.

Bots are signing up for accounts, but the CAPTCHAs puzzles themselves are being solved in 21st century sweatshops, where workers in India are paid as little as $4 a day to defeat security checks. The images they decipher are thought to be served up to them by specialist applications for maximum efficiency.

Previous approaches to busting CAPTCHAs have included a virtual stripper program, revealing progressively more flesh in return for deciphering the text in a displayed image, which users were unaware actually came from a web service sign-up CAPTCHA.

News Source: The Register