This indicates an attack attempt against a Memory Corruption vulnerability in Adobe Reader and Adobe Acrobat.
The vulnerability is caused by an error that occurs when the vulnerable
software handles a malicious PDF file. A remote attacker may exploit this to
execute arbitrary code via a crafted PDF file.
Adobe Reader X (10.1.1) and earlier 10.x versions
Adobe Reader 9.4.6 and earlier 9.x versions
Adobe Acrobat X (10.1.1) and earlier 10.x versions
Adobe Acrobat 9.4.6 and earlier 9.x versions
System Compromise: Remote attackers can gain control of vulnerable systems.
Refer to the vendor's website for suggested workaround.