Microsoft has released a security alert. There is a team at Microsoft that is dedicated to these kinds of crisis situations.

They publish their findings at microsoft.com/security.

If you find a new exploit, or know of some security problem on one of our products, please send email to secure@microsoft.com.

Already this page has been updated a few times in the past 24 hours. If you think you have a security problem with a Microsoft product, please check the security site.

If you just want to make sure you are protected, then visit microsoft.com/protect.