Spammers Creating Automated Accounts at Gmail

Websense, an Internet security company, reported on February 22, 2008 that cyber criminals have developed bots that are capable to create fake Gmail accounts and allow sign up in the account. They are purposely designed to spread spam and to defeat Captcha-based security.

Completely Automated Public turning test to tell Computers and Humans Apart (Captcha) is a challenge response program that helps in distinguishing between human user and an automated program. When a user creates an account, Captcha does not allow user to create account until he fills the letter given in the image.

The technique has been used by renowned Websites like Gmail and Yahoo Mail to prevent automatic sign up to e-mail accounts. However, hackers have been able to break its security. HotLan Trojan is a perfect example of how hackers are succeeding in creating fake e-mail accounts. HotLan Trojan created over 500, 000 spam e-mails on Hotmail, Gmail and Yahoo since it appeared in July 2007.

Websense claims that recent Gmail Captcha hack is the most sensitive it has identified. Generally, Live Mail Captcha hacking requires only one zombie host to perform the whole job but in Gmail, two compromised hosts are needed. Both zombie hosts take different courses to analyze Captcha at Gmail.

By using two different techniques, one in each five attempts of Captcha breaking becomes successful. The percentage is quite low but sufficient in case of automated strikes.

Undoubtedly, it takes lots of effort in creating one account at Gmail but each account has unprecedented advantages for spammers. Moreover, availing general services of Google are fruitful for spammers because by these, they get access of address that is possibly not blacklisted. It helps them to break one aspect of anti-spam defenses.

Besides, Websense also reported that the US-based domain is hosting a large number of Captcha breaking services. The page comprises of a payment advice and support page together with an internal test page.

Cyber criminals belong to the same group that broke Windows Live Mail CAPTCHAs in the beginning of February 2008, believe the Websense researchers. The attack seems to have been installed on hacked systems forming a large botnet that create e-mail accounts automatically. Later on, these e-mail accounts are used to send spam messages.

Related article: Spammers Continue their Campaigns Successfully

» SPAMfighter News - 3/4/2008