There's an evil security flaw in many Windows-based computers that exploits code related to animated cursors. It's bad enough that Microsoft is releasing a security patch ahead of its regular release date. The exploit is particularly easy to unwittingly pick up, so you should get the patch right away.
Security firm F-Secure said attacks using the flaw related to cursor animation files used by Windows intensified over the weekend, with the majority tracing back to different Chinese hacker groups.
It said most of the activity around the so-called ANI exploit has been via dozens of malicious Web sites but warned that on Sunday the first Internet worm, able to replicate without the user doing anything to the machine, was found using the flaw to spread.
"This vulnerability is really tempting for the bad guys," said Mikko Hypponen, chief research officer at F-Secure. "It's easy to modify the exploit, and it can be launched via Web or e-mail fairly easily."