This indicates an attack attempt to exploit an Information Disclosure vulnerability in Adobe Reader And Acrobat.
The vulnerability is due to insufficient input validation when the vulnerable software handles a maliciously crafted PDF file. A remote attacker can exploit this to gain unauthorized access to sensitive information.
Adobe Reader XI (11.0.09) and earlier 11.x versions
Adobe Reader X (10.1.12) and earlier 10.x versions
Adobe Acrobat XI (11.0.09) and earlier 11.x versions
Adobe Acrobat X (10.1.12) and earlier 10.x versions
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems.
Apply the most recent upgrade or patch from the vendor.