This indicates an attack attempt against a integer overflow vulnerability in Adobe Flash Player.
The vulnerability is caused by an error when the vulnerable software handles a specially crafted SWF file. It allows a remote attacker to execute arbitrary code.
Adobe Flash Player version 188.8.131.52 and previous versions
Adobe Flash Player version 10.0.22.87 and previous versions
Adobe AIR version 1.5.1 and previous versions
System Compromise: Remote attackers can gain control of vulnerable systems.
Denial of Service: Remote attackers can crash vulnerable systems.