Yahoo antispam protection cracked by “Russian security experts”?

28th January 2008

Some “Russian expert on security” argues that he was able to write a program, which, in 35% of cases, can pass over spam-protection tools, used by Yahoo, reports Information Week.
CAPTCHA (an abbreviation indicating Completely Automated Public Turing test to tell Computers and Humans Apart) is one of the most common methods of fighting against spam-robots. As a rule, CAPTCHA just shows a picture with several highly distorted symbols that people can understand (and correctly put these characters into the field) but a machine can not.
Though, there are many programs managing to cope with CAPTCHA, that variation of CAPTCHA used by Yahoo, Google and some other major portals still remains inaccessible.
However, the abovementioned “security expert” wrote in his blog at Blogspot.com, some time ago, that he and his associates had received information about the existence of a new means of overcoming CAPTCHA, with the efficiency up to 30%. And this is already a very significant fact, given that the robot could, if necessary, attack the same resource up to 100 thousand times a day.
His explanations do not really clear how this new tool works, but “safety specialists” from Russia have already published on “Rapidshare” a file with an example.
If the functionality of this tools is confirmed, we can wait for increasing spam on Yahoo mail-servers.