Fake security software in millions of computers

Tens of millions of U.S. computers are loaded with scam security software that their owners may have paid for but which only makes the machines more vulnerable, according to a new Symantec report on cybercrime. Cyberthieves are increasingly planting fake security alerts that pop up when computer users access a legitimate website. The "alert" warns them of a virus and offers security software, sometimes for free and sometimes for a fee. "Lots of times, in fact they're a conduit for attackers to take over your machine," said Vincent Weafer, Symantec's vice president for security response