This indicates an attempt to exploit a Memory Corruption vulnerability in Microsoft Visio.
The vulnerability is caused by an input validation error that occurs in DWGDP.DLL while processing malformed DXF files. It allows remote attackers to crash the vulnerable software or execute arbitrary code via a crafted DXF file.
Microsoft Visio 2010 Service Pack 1
Microsoft Visio Viewer 2010 Service Pack 1
System Compromise: remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.