Microsoft posted information tonight to help customers with a Windows and MSN Messenger issue related to MS05-009. Key to protecting yourself is making sure that you've installed the MS05-009 update. Get the details here:
Protect Against Exploit Code Related to Security Bulletin MS05-009
Microsoft is aware of exploit code available on the Internet that seeks to exploit an issue addressed this week by the update released with Microsoft Security Bulletin MS05-009. Microsoft is not currently aware of any active attack utilizing this code or any customer impact. We will continue to actively monitor the situation and provide updated customer information and guidance as necessary.
Our investigation of this exploit code has verified that it does not affect users who have installed the MS05-009 update for both Microsoft Windows and MSN Messenger. Microsoft continues to recommend customers apply the MS05-009 updates to the affected products by enabling Automatic Updates in Windows as well as installing the updated version of MSN Messenger.