The exploit code has been released for the MS05-009 vulnerability. The vulnerability is exploitable via Portable Network Graphics (PNG) images.

According to Microsoft, this vulnerability affects Microsoft's MSN Messenger, Windows Messenger and Windows Media Player: a hostile PNG image can be used to execute arbitary code on the vulnerable system.

Previosly GIF and JPEG processing among others on various platforms have had similar vulnerabilities.

Since the fix is available, it is time to apply some patches right now.