Several banner ads containing Trojan horse programs that can compromise a user's computer have been running on some high-traffic Web sites for the past several weeks, including MySpace.com and Photobucket.com, Security Fix has learned.
Web security company ScanSafe said it first spotted the tainted banner ads on Aug. 8, and estimates that the hostile ads ran several million times for the next three weeks. Other sites that ran the ads included Bebo.com, TheSun.co.uk, and UltimateGuitar.com, officials at ScanSafe said. All a visitor to one of these sites needed to do to infect their machines was to browse a page that featured the ads with a version of Internet Explorer that was not equipped with the latest security updates from Microsoft.
Just another reason to use firefox and adblock.
and also virtualization programs