ThreatFire AntiVirus Free Edition 3

Threatfire runs in addition to any adware, spyware or anti-virus software you already have. This is the only program I know that can do this with no interference to your existing internet security.Easy to setup and use, giving you a little more peace of mind. The interface is simple giving you straight-forward options.If it suspects there is a threat to your PC that is not in it's database, but fits a profile of a threat it will prompt you for a response, protecting you from possible UNknown threats.Recommend this software as excellent support for your existing PC security.

It has a lot of features and great heuristics and it has a good amount in its' database and it is easy to scan and update. The scan looks at many things and you can choose which type of scan you want. Overall it is a great choice while running with a primary security program.