subdomain-bruteforcer v1.0

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 performs subdomain enumeration about 8 times faster than Fierce, and can chew through 31k lookups in about 5 minutes on a home cable connection.

Why is this tool so fast?

Other multi-threaded subdomain enumeration tools that I have seen are bottlenecked by using a single resolver. In SubBrute, each thread is given its own slice of the resolvers list (resolvers.txt) so that a single resolver isn’t overwhelmed. The subdomain list (subs.txt) is sorted by frequency, so this tool will return the most common domains quickly.

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 -f full.html > my_subs.txt

I used this feature to create subs.txt which contains 31291 subdomains. subs_small.txt was stolen from fierce2 which contains 1896 subdomains. If you find more subdomains to add, open a bug report and I’ll be happy to add them!

Easy to install: You just need and python2.7 or python3. This tool should work under any operating system: bsd, osx, windows, linux…

(On a side note giving a makefile root always bothers me, it would be a great way to install a backdoor…)

Under Ubuntu/Debian all you need is:

sudo apt-get install python-dnspython

On other operating systems you may have to install dnspython manually:

Easy to use:


Tests multiple domains: ./

or a newline delimited list of domains: ./ -t list.txt

Also keep in mind that subdomains can have subdomains (example:

./ > gmail.out

./ -t gmail.out



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