This indicates an attack attempt to exploit an Integer Overflow vulnerability in Adobe Acrobat Reader.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted PDF file. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted PDF file.
Acrobat XI 11.0.11 and earlier versions Windows and Macintosh
Acrobat X 10.1.14 and earlier versions Windows and Macintosh
Reader XI 11.0.11 and earlier versions Windows and Macintosh
Reader X 10.1.14 and earlier versions Windows and Macintosh
System Compromise: Remote attackers can gain control of vulnerable systems.
Refer to the vendor's advisory for updates: