This indicates an attack attempt against a remote code execution vulnerability in Microsoft Visio.
The vulnerability is caused by an error when the vulnerable software handles a specially crafted Visio (.VSD) file. It allows a remote attacker to execute arbitrary code.
Microsoft Office Visio 2002 Service Pack 2
Microsoft Office Visio 2003 Service Pack 3
Microsoft Office Visio 2007 Service Pack 1
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply patch, available from the website: