Fierce

Fierce is an open source active recon tool to enumerate sub domains of a target website. This tool was written by Robert (RSnake) Hansen and comes pre-installed by default in Kali Linux.

The Fierce Perl script applies techniques such as zone transfer and wordlist brute-forcing to find subdomains of the target domain:

fierce -dns target.com

Let's run Fierce against iitk.ac.in and see how it performs. It is shown in the following screenshot:

Fierce

Voila, Fierce presented us with a list of subdomains. One thing to note is that Fierce enumerated the name servers of iitk.ac.in, and then tried to do a zone transfer on each. Luckily one of the name servers ...

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