This indicates an attack attempt to exploit a remote Code Execution vulnerability in Windows.
The vulnerability is due to an error when the vulnerable software handles a call flaw. An attacker who successfully exploits this vulnerability can run arbitrary code on a medium integrity level.
Windows Server 2003
Windows Server 2008
Windows Server 2008 R2
Windows 8 and Windows 8.1
Windows Server 2012 and Windows Server 2012 R2
Windows RT and Windows RT 8.1
Server Core installation option
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.