This indicates an attack attempt against a memory-corruption vulnerability in Adobe Reader and Acrobat, which could lead to arbitrary code execution.
Adobe Reader 9.3.2 and earlier versions for Windows, Macintosh, and UNIX
Adobe Acrobat 9.3.2 and earlier versions for Windows and Macintosh
System Compromise: Remote attackers can gain control of vulnerable systems.
Refer to the vendor's advisory: