Thousands Snared by Malware Warning from Big-Name Web Sites

Thousands of PC users have been duped into surrendering sensitive information and installing malicious software after falling victim to a complex scam that continues to plague well-known web sites. The scam is the latest to piggyback on banner ads that are fed to high-traffic destinations. Malicious code hardwired into the ads prompts a pop-up that warns of a bogus security threat on the visitor’s machine. It offers to fix the problem in exchange for a fee and for credit card information. The ad then attempts to install a back door on the victim’s machine