If you aren't already aware from press articles or the Microsoft Security Advisory, there are reports of an attack exploiting a vulnerability in the DNS Server Service in Windows 2000 Server SP4, Windows Server 2003 SP1, and Windows Server 2003 SP2. The attack could allow remote code execution.
Folks in the MSRC say "At this time, the attack does not appear widespread." The FAQ with the Security Advisory says "Microsoft is completing development of a security update for Windows that addresses this vulnerability."
