Last modified 8 years ago Last modified on 08/03/10 03:13:21

Fierce Domain Scan

Fierce domain scanner

Fierce Domain Scan was born out of a frustration while performing a web application security audit. It used to be very time-consuming to discover large swaths of a non-contiguous corporate network, but it doesn't have to be. It's terribly easy to run a scanner against an IP range, but if a network's web presence is distributed across multiple ranges, you can miss huge chunks of networks. Fierce helps solve that problem.

Fierce is a reconnaissance tool written in Perl that quickly scans domains (usually in just a few minutes, assuming no network lag) using a variety of techniques to locate undocumented, internal or just hard-to-find resources via the DNS system.

Latest version Fierce v2

To check out the latest version of Fierce v2 from subversion, simply run the following command:

 svn co fierce2/

You can find the documentation here: Installing and Updating


To access the documentation for Fierce v2 use the following command:

 man fierce

Additionally, the following resources may be helpful:

  • Examples - Specific examples of using Fierce v2.
  • Techniques - Details for all of the techniques used by Fierce v2.
  • Installing - Documentation for installing Fierce v2.
  • Updating - Documentation for updating Fierce v2.
  • Fierce::Parser - Documentation on Fierce::Parser XML Parser
  • Contributing - Notes for anyone that wants to contribute to Fierce v2.

Bugs / Feature Requests / Patches

Bugs, Feature Requests and Patches can be submitted via email to: fierce [ the at sign ] You need to register on

If you don't feel like registering, send feedback to jabra [ - at - ] spl0it [ dot ] org.

My GPG key can be found at