Firms urged to use unofficial Windows patch

Antivirus vendor F-Secure and the Internet Storm Center, a volunteer security group, separately urged businesses on Tuesday to use the unofficial patch, as Microsoft has not yet offered an authorized fix for the problem.
Microsoft, though, has advised businesses not to use third-party updates, even though its own patch won't be available until next Tuesday.
The WMF vulnerability can be exploited in Windows XP with Service Pack 1 and 2, as well as Windows Server 2003, security experts said.

Here is the third-party patch