Microsoft released the v1.11 of its malicious software removal tool, which removes Sony BMG's copy protection sceme found on some of the company's music CDs.
In addition, the removal tool helps detect and remove current, prevalent malicious software. This malicious software includes viruses, worms, and Trojan horses.
Microsoft rates the severity of Sony's "F4IRootkit" software as "moderate", which means that its its exploitability is mitigated to a significant degree by factors such as default configuration, auditing, or difficulty of exploitation.
Download Microsoft's Removal Tool at http://www.microsoft.com/downloads/details.aspx?FamilyId=AD724AE0-E72D-4F54-9AB3-75B8EB148356&displaylang=en
Note that each release of the tool helps detect and remove all the malicious software covered in earlier versions. Release information for the v1.11 of the software is available here