Three days ago Microsoft noticed their DirectX has a serious vulnerability. A hacker could exploit the way DirectX's MJPEG decoder codec handles MJPEG streams in avi and asf files. Not only do you have to worry about opening avi and asf files though, DirectX also has another vulnerability. Hackers can also use an old technique called .sami file parsing to exploit the way DirectX handles it's supported format files.

I expect that soon hackers will be flooding the net with infected avi files so you better go download Microsoft's patch for DirectX. They haven't added this update to the automatic updates yet either! Im assuming they haven't because some people have experienced system conflicts with the patch. So therefore I suggest a quick backup before updating if it's possible. I updated without backing up of course though cause Im a rebel risk taker, and because I know the consequences of getting infected are much worse than the consequences of having a system conflict.