This is a (fast) multi-threaded python tool for enumerating subdomains. This tool also contains a large list of real subdomains that you will find in the wild. Basically I was fed up with fierce / fierce2, and every other tool I used so I wrote something way faster in python. This tool will “just work”, and work well. By default this tool does subdomain enumeration about 8 times faster than Fierce, and can chew through 31k lookups in about 5 minutes on a home cable connection.A notable improvement over every other subdomain bruteforcing tool out there is that this tool has an awesome subdomain list and I included an awesome and flexible mangling feature to build your own subdomain list.

Using some creative google hacks I put together a disorganized list of well over a million domain names, I then used a regex to rip out the subdomains and then sorted them by frequency. You can also use this data-mangling feature by using using this simple command: python subroute.py -f full.html > my_subs.txt

I used this feature to create subs.txt which contains 31280 subdomains. subs_small.txt was stolen from fierce2 which contains 1896 subdomains.

Having a list of resolvers (resolvers.txt) is best for a multi-threaded application because most dns resolvers have rate-limiting by default. This feature is for speed.

Easy to install : You just need http://www.dnspython.org/ and python2.7, should work under any operating system: bsd, osx, windows, linux…

Under Ubuntu/Debian all you need is: 
sudo apt-get install python-dnspython

Easy to use: 
./subbrute.py target.com

Download : Zipball | Tarball
For More Information and Other Version: right here