URL Rewriting and Analysis Best Practices

URL Defense Guide using Cisco Secure Email

Best Practices with URL Rewriting and Analysis

From our Gold Config + Best Practices we provide the email administrator configuration that Cisco recommends in order to utilize Outbreak Filters for URL defense.

Security Services > Outbreak Filters

  • Enable Security Services > Outbreak Filters
  • Enable Outbreak Filters Adaptive Rules
  • Set maximum message size to scan at 2M
  • Enable Web Interaction Tracking

Incoming Mail Policies > Outbreak Filters for Default

  • The default threat level is 3, please adjust as per your security requirements
    • Quarantine Threat Level: If the threat level for a message equals or exceeds this threshold, the message will be sent to the Outbreak Quarantine. (1=lowest threat, 5=highest threat)
  • Enable message modification
  • URL Rewriting set for "Enable for all messages"
  • Change Subject prepend to [Possible $threat_category Fraud]
  • (Optional) Bypass domain scanning
    • All destinations and clients in this list will bypass the Cisco Security Proxy.
    • Separate multiple entries with commas. Valid formats:
      • CIDR addresses such as, 2001:db8::/32
      • An IP address such as, 2001:420:80:1::5
      • a hostname such as crm.example.com
      • a partial hostname such as .example.com
      • a domain such as example.com