Hitman Pro is an on-demand malware scanner and removal tool. It will usually do a full-system scan significantly faster than other (traditional) solutions due to its cloud-based scan technique. It does not offer a real-time component (aka shield, guard) and will upload suspicious files to the cloud for scanning.
Hitman Pro markets itself as a 'Second Opinion' malware scanner and offers free unlimited scanning and a free 30-day evaluation license (easily obtained with one click from within the program) to allow for removal of found infections.
Its approach of finding malware differs from most 'traditional' anti-virus and anti-malware scanners in that it uploads suspicious files to a computer network (the 'cloud') on the internet where files are being scanned by different anti-virus engines - as of October 2010 these are Emsisoft, Dr.Web, G Data, IKARUS, PrevX.
The program itself contains none of these scan engines and only classifies files by comparing the file signature to a list of files that are either known to be safe or malicious.
In addition the program includes a behavioral scanner and a removal component.