The exploit works when unsuspecting WoW players visit any number of Web sites infected by the hackers with keylogging software. When the players visit the sites--which are often unrelated to WoW, but that players frequent, Thompson said--the software is quietly installed on their computers, allowing the hackers to spy on keystrokes and steal players' WoW passwords.

While the software could easily be used to hack into players' accounts in almost any online game, there's no evidence the victims are anybody but players of WoW.