Earlier this week the exploit code for a highly critical Windows vulnerability affecting all versions of Windows from XP to 7 was made public. The bad news is that malware developers are already actively exploiting this bug. Symantec has identified that the W32.Stuxnet worm, which spreads using this vulnerability, has already affected thousands of systems.
The Shell Shortcut Parsing vulnerability is a particularly worrisome bug because there aren’t a lot of things a user can do to protect himself. Even if autorun and autoplay is disabled, users can still get infected. All that the user is required to do is to open the compromised device, network share or WebDav. The only preventive measure is to disable icon rendering. However, doing so will basically cripple the Windows environment. To make matters worse, Steve Gibson from GRC research is claiming that a security researcher has already figured out a way to exploit this vulnerability through favicons.
Microsoft is obviously working hard to patch this severe vulnerability. However, an official patch may take weeks to come. Until then, ensure that your system has up-to-date malware protection, and avoid using Internet Explorer (other browsers can also be exploited, but possibly to a lesser degree).