Google's PC search software is vulnerable to a variation on a little-known Web-based attack called anti-DNS pinning that could give an attacker access to any data indexed by Google Desktop, security researchers said this week.

Hansen and Grossman say that Google is not the only company vulnerable to a growing category of Web-based attacks. For instance, MySpace.com was hit when a fast-moving worm spread through the MySpace community in early December, stealing MySpace log-in credentials and promoting adware Web sites.

"A lot of these new attack techniques are going to require the browsers to improve," Grossman said. "The users really have very little ability to protect themselves against these attacks" he said. "It's very bad. Even the experts are afraid to click on each other's links anymore."