This indicates an attempt to exploit a memory corruption vulnerability in Adobe Reader.
The vulnerability is caused by an error that occurs when the vulnerable software parses a malformed CLOD Progressive Mesh Continuation Block in U3D file embeded in a PDF files. It allows a remote attacker to execute arbitrary code via sending a crafted PDF file.
Adobe Reader 9.1.3 and older versions.
System Compromise: Remote attackers can gain control of vulnerable systems.
Currently we are not aware of any vendor supplied patch for this issue.