This indicates an attack attempt to exploit a Memory Corruption vulnerability in Adobe Flash Player.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted SWF file. A remote attacker may be able to exploit this to execute arbitrary code within the context of the affected application, via a crafted SWF file.
Adobe Flash Player Desktop Runtime 22.214.171.124 and earlier - Windows and Macintosh
Adobe Flash Player Extended Support Release 126.96.36.1998 and earlier - Windows and Macintosh
Adobe Flash Player for Google Chrome 188.8.131.52 and earlier - Windows
Adobe Flash Player for Google Chrome 184.108.40.206 and earlier - Macintosh
Adobe Flash Player for Internet Explorer 10 and Internet Explorer 11 220.127.116.11 and earlier - Windows 8.0 and 8.1
Adobe Flash Player 18.104.22.1684 and earlier - Linux
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.