As noted in the article, only certified patches from Microsoft should be installed as it could create issues and conflicts later with future security updates. 

Russian Security Firm finds XP SP2 Vulnerable & issues patch
http://www.techweb.com/wire/security/59200229

A little-known Russian security firm claimed Monday that it's spotted vulnerabilities in Microsoft Windows XP SP2, and has taken the unusual step of producing its own patch for the bug.
Researchers at Moscow-based Positive Technologies said that they uncovered the flaws in Windows XP SP2's DEP (Data Execution Mechanism) back in early October, and reported it to Microsoft more than a month ago.  When it didn't receive a response, Positive released details of the vulnerability on its Web site, and posted a patch that supposedly temporarily fixes the problem.