From PC Tools:

ThreatFire uses advanced patent-pending technology to detect signs of malicious behavior commonly used by malware threats. ThreatFire is unlike traditional antivirus products that rely on old fashioned \"signature\" technology and require updating every time a new threat occurs.

By constantly monitoring the activity on your PC ThreatFire\'s ActiveDefense technology is able to hunt down and paralyze threats that are too new or too clever to be recognized by traditional security software.

ThreatFire employs an intelligent behavioral engine to only alert you on truly malicious behavior, because sometimes even legitimate software may look malicious. This means you are only alerted when you really need to be.