This indicates an attempt to exploit an arbitrary command execution vulnerability in Comodo Antivirus.
The vulnerability is caused by an input validation error in the "Cavutil.Utility.1" ActiveX control, in the "ExecuteStr()" method. It allows remote attackers to execute arbitrary commands by tricking a user into visiting a specially crafted web page.
Comodo AntiVirus 2.0
System Compromise: remote attackers can gain control of vulnerable systems.
Set the kill bit for CLSID "309F674D-E4D3-46BD-B9E2-ED7DFD7FD176".
Microsoft Knowledge Base Article details the "kill bit" mechanism.