ZyXEL Communications 1000 Manuel D’Utilisation

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Chapter 33 Anti-Virus
ZyWALL USG 1000 User’s Guide
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33.1.2  What You Need to Know 
Anti-Virus Engines
Subscribe to signature files for ZyXEL’s anti-virus engine or one powered by 
Kaspersky. When using the trial, you can switch from one engine to the other in 
the Registration screen. After the trial expires, you need to purchase an iCard for 
the anti-virus engine you want to use and register it in the Registration > 
Service
 screen. You must use the ZyXEL anti-virus iCard for the ZyXEL anti-virus 
engine and the Kaspersky anti-virus iCard for the Kaspersky anti-virus engine. See 
 for details.
Virus and Worm
A computer virus is a small program designed to corrupt and/or alter the 
operation of other legitimate programs. A worm is a self-replicating virus that 
resides in active memory and duplicates itself. The effect of a virus attack varies 
from doing so little damage that you are unaware your computer is infected to 
wiping out the entire contents of a hard drive to rendering your computer 
inoperable. 
ZyWALL Anti-Virus Scanner
The ZyWALL has a built-in signature database. Setting up the ZyWALL between 
your local network and the Internet allows the ZyWALL to scan files transmitting 
through the enabled interfaces into your network. As a network-based anti-virus 
scanner, the ZyWALL helps stop threats at the network edge before they reach the 
local host computers. 
You can set the ZyWALL to examine files received through the following protocols: 
• FTP (File Transfer Protocol)
• HTTP (Hyper Text Transfer Protocol)
• SMTP (Simple Mail Transfer Protocol) 
• POP3 (Post Office Protocol version 3)
• IMAP4 (Internet Message Access Protocol version 4)
 How the ZyWALL Anti-Virus Scanner Works
The following describes the virus scanning process on the ZyWALL. 
1
The ZyWALL first identifies SMTP, POP3, IMAP4, HTTP and FTP packets through 
standard ports.