Spammers are using a virtual stripper as bait to dupe people into helping criminals crack codes they need to send more spam or boost the rankings of parasitic Web sites, security researchers said Tuesday.
A series of photographs shows "Melissa," no relation to the 1999 worm by the same name, with progressively fewer clothes and more skin each time the user correctly enters the characters in an accompanying CAPTCHA (Completely Automatic Public Turing Test to Tell Computers and Humans Apart), the distorted, scrambled codes that most Web mail services use to block bots from registering hundreds or thousands of accounts. Spammers rely on Web e-mail accounts because they're disposable; by the time filters have blocked the address, the spammers throw it away and move on to another.
The CAPTCHAs that Melissa feeds to users are, in fact, legitimate codes snatched from Yahoo Mail's signup screens, said analysts at Trend Micro Inc. The hackers, frustrated at their inability to come up with a way to automate account registration, are getting users to do their dirty work.