Captchas not so good any more

Feb 26, 2008 20:11 GMT  ·  By

The spam-free Gmail is about to become spam-full and on an accelerated rate from now on. When the email service from Google first came to be, it prided itself with its filters that would redirect spam directly to the folder specially created for it. Slowly but surely, hackers managed to evolve methods of fooling the rigid filters and some unwanted messages started finding their way into users' inboxes.

The next step was to create as many Gmail accounts as possible but Captchas (Completely Automated Public Turing test to tell Computers and Humans Apart) stopped this attempt fairly well. Until now. After successfully hacking their way into fooling the Windows Live captcha used by Hotmail, cyber criminals took a poke at Google's mail service and it turned to be a poke in the eye. Internet security firm Websense reports that the captchas used by Gmail have been defeated by the bots created with just that purpose.

Ever growing in number, the methods of fooling the captchas have crowned king the record breaking HotLan Trojan, which managed to create some 500,000 spam email accounts with Hotmail, Yahoo! and Gmail in just little over 6 months of 'activity.' The latest hack that is able to go through the captcha defense is by far the most promising, it manages to create a spam account for every five attempts it makes. Not a very impressing percentage, but it is sophisticated enough, using two zombies (compromised hosts) for the job, and each of those uses a different technique to analyze the captcha.

Gmail is the holy land for spammers because it grants many advantages. Apart from gaining access to all of the Google services, it also has the advantage of not being in danger of having the domain blacklisted, and it's free, let's not forget about that.

A new age is upon us, spam-wise. The Gmail team should be on the lookout now, and slowly eliminate the proven spam addresses as well as working some more on their captcha system, if it is the one they will be sticking to in the future,