Cisco Cisco Web Security Appliance S670 Betriebsanweisung

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Cisco AsyncOS for Web User Guide
 
Chapter 13      Configuring Security Services
  Overview of Anti-Malware Scanning
Webroot Scanning
The Webroot scanning engine inspects objects to determine the malware scanning verdict to send to the 
DVS engine. The Webroot scanning engine inspects the following objects:
URL request. Webroot evaluates a URL request to determine if the URL is a malware suspect. If 
Webroot suspects the response from this URL might contain malware, the appliance monitors or 
blocks the request, depending on how the appliance is configured. If Webroot evaluation clears the 
request, the appliance retrieves the URL and scans the server response.
Server response. When the appliance retrieves a URL, Webroot scans the server response content 
and compares it to the Webroot signature database. 
McAfee Scanning
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
Matching Virus Signature Patterns
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
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.