The "Threat Behavior ID" is part of the cleaning feature of Malware Behavior Blocking. There is no direct threat associated to this log because OfficeScan Behavior Monitoring only looks at the potential malware behavior. The log either matches an exact malware name/family or not.

When you select the Enable Malware Behavior Blocking option on Behavior Monitoring settings, this log will appear upon termination of a potential threat process.

To know more about Behavior Monitoring, check the OfficeScan documentation.