http://www.microsoft.com/technet/security/advisory/925984.mspx
What's it's about: Vulnerability in PowerPoint Could Allow Remote
Code Execution 
same as last month.
Versions affected: PowerPoint 2000, PowerPoint 2002, PowerPoint
2003, PowerPoint 2004 for Mac, PowerPoint v. X for Mac
No patch is available yet.
Same precautions applied. Do not open anything from unknown
sources. Even if you know, do be careful.
Another way would be to open the PowerPoint file in PowerPoint
Viewer.
http://www.microsoft.com/downloads/details.aspx?familyid=428d5727-43ab-4f24-90b7-a94784af71a4&displaylang=en
Mac users take note. You too are affected. If you are not using
Microsoft products, then skip this.