Cisco Cisco Web Security Appliance S370 Guia Do Utilizador

The McAfee scanning engine inspects objects downloaded from a web server in HTTP responses. After 
inspecting the object, it passes a malware scanning verdict to the DVS engine so the DVS engine can 
determine whether to monitor or block the request.

The McAfee scanning engine uses the following methods to determine the malware scanning verdict:

Matching virus signature patterns

Heuristic analysis

McAfee uses virus definitions in its database with the scanning engine to detect particular viruses, types 
of viruses, or other potentially unwanted software. It searches for virus signatures in files. When you 
enable McAfee, the McAfee scanning engine uses this method to scan server response content.

Heuristic analysis is a technique that uses general rules, rather than specific rules, to detect new viruses 
and malware. When the McAfee scanning engine uses heuristic analysis, it looks at the code of an object, 
applies generic rules, and determines how likely the object is to be virus-like.

Using heuristic analysis increases the possibility of reporting false positives (clean content designated 
as a virus) and might impact appliance performance.When you enable McAfee, you can choose whether 
or not to also enable heuristic analysis when scanning objects.