ThreatFire is a Free Antivirus from PC Tools. The unique feature of ThreatFire is that it has behavior based detection, to detect never before seen Viruses and malicious software.
ThreatFire provides an additional layer of protection to your PC. It is not a replacement for a regular antivirus, but to run along side that. So, your antivirus can protect your computer against known virus threats, and PC Tools ThreatFire can protect against unknown zero-day threats.
ThreatFire continually protects your PC against attacks by detecting malicious behavior, such as capturing your keystrokes or stealing your data, instead of only looking for known threats like normal antivirus software. By implementing sophisticated real-time behavioral analysis ThreatFire is able to stop never- before-seen “zero-day” threats solely by detecting their malicious activity.
Whenever ThreatFire detects a malicious activity, it compares the malicious software with the database of known threats. If it finds a match there, then it quarantines the malicious software. If it doesn’t finds a match there, then it calculates threat level based on advanced algorithms, and then present recommendation to user, who can choose to quarantine the software or ignore it.
ThreatFire is able to protect against spyware, adware, keyloggers, viruses, worms, Trojans, rootkits, buffer overflows, and other malware.
ThreatFire is light on system resources, and you will almost never even notice it (unless it detects something). It provides Real-time behavior-based protection, and comes with Automatic Smart updates and Advanced custom rules.
Download links, and video tutorials at the end.