COMODO IS is a free/paid security suite that has an Antivirus Engine, Firewall, HIPS detection engine and Sandbox. It works on a 'default deny' system, rather than a 'default allow' (blacklist) system, which allows it to protect your computer more effectively.
CHANGED! Default maximum file size to be scanned has been changed from 20 MB to 40 MB
Download Link: Official Website
News Source: COMODO forum announcement