Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

Página de 460
C H A P T E R
 
10-1
Cisco IronPort AsyncOS 7.6 for Email Configuration Guide
OL-25136-01
10
Outbreak Filters
Low-volume, targeted email attacks such as phishing messages, scams, and malware links are on the rise 
while viruses spread through attachments are on the decline. The messages used for these non-viral 
attacks are complex and evolving; they are professional-looking messages that use social engineering 
tricks, including using the recipient’s information, in an attempt to trick the recipient into clicking 
custom URLs that point to phishing and malware websites. These URLs can be unique for each recipient 
or a small group of recipients and these websites are online only for a short period of time and are 
unknown to web security services. All of these factors make these small scale, non-viral outbreaks more 
difficult to detect than widespread virus outbreaks and spam campaigns. Cisco IronPort’s Outbreak 
Filters feature protects your users from this growing trend of targeted attacks in addition to new virus 
outbreaks.
  •
  •
  •
  •
  •
  •
Outbreak Filters Overview
Messages designed to steal sensitive information from users or deliver malware to their computers 
continue to evolve and can slip by traditional anti-virus and anti-spam scanning software. Outbreak 
Filters act proactively to provide a critical first layer of defense against these new outbreaks. By 
detecting new outbreaks in real-time and dynamically responding to prevent suspicious traffic from 
entering the network, Cisco IronPort’s Outbreak Filters feature offers protection until new anti-virus and 
anti-spam updates are deployed. The Outbreak Filters use Cisco IronPort’s outbreak detection 
technology and intelligent quarantine system to protect your users.
The Outbreak Filters feature protects your users and your network by gathering information about 
outbreaks as they occur and using this data to prevent the spread of these outbreaks to your users. 
Outbreak Filters compares incoming messages with published Outbreak Rules from Cisco Security 
Intelligence Operations (SIO) to determine if the message is a part of a large-scale virus outbreak or a 
smaller, non-viral attack. AsyncOS assigns messages that match the Outbreak Rules a threat level that 
indicates the severity of the message’s threat and compares that threat level to the quarantine and 
message modfication thresholds you set for your mail policy. Messages that meet or exceed one of those 
thresholds are quarantined or modified to protect the recipient.