Posted by Virus Bulletin on Jun 3, 2008
Loophole in Google's AdSense solved, but new flaw quickly uncovered.
The good name of web giant Google continues to be a popular source of legitimacy among spammers, despite their efforts to shut down loopholes open to abuse.
Last month, Google fixed an open redirect in its AdSense ad serving program. The open redirect had become popular with spammers trying to lure users into clicking their links, as they could be made to look like safe URLs within Google's domain. Of course, in the best of cases these links redirected to a spamvertising website, but more commonly, and more dangerously, they took victims to sites pushing drive-by downloads of malware. In either case, as they resided on the popular Google domain, the URLs were unlikely to be blacklisted.
With the loophole closed only a few weeks, spammers have quickly found themselves another open redirect to stealthily push their malicious websites. This redirect resides on the domain of ad-serving firm DoubleClick, a company that was, coincidentally, acquired by Google earlier this year. It is believed that DoubleClick is aware of the open redirect.