Haven't tried it, and don't think I really have any need for it, but seems like one of the better freebies (one year license) to be given away on GAOTD:
http://www.giveawayoftheday.com/mamutu/
Mamutu monitors in realtime all active programs for dangerous behavior and blocks malicious activities. It recognizes new and unknown Trojans, Backdoors, Keyloggers, Worms, Viruses, Spyware, Adware and Rootkits (Zero-Day attacks), without the need of daily signature updates. Mamutu gives you full control over internal system activities. It’s small but very powerful. Mamutu saves resources and does not slow down the PC.Features:
* Monitors live all active programs for dangerous behavior (Behavior Blocking);
* Recognizes new and unknown Trojans, Worms and Viruses (Zero-Day attacks), without daily updates;
* Small but very powerful. Saves resources and does not slow the PC down.
Please note that Mamutu@GAOTD comes with full license including updates and techsupport.