Altdns

DEPRECATION NOTICE!

I have written the same tool using golang. The result was 2x speed and many new options.

Take a loot if you want :)

Subdomain discovery through alterations and permutations

Altdns is a DNS recon tool that allows for the discovery of subdomains that conform to patterns. Altdns takes in words that could be present in subdomains under a domain (such as test, dev, staging) as well as takes in a list of subdomains that you know of.

From these two lists that are provided as input to altdns, the tool then generates a massive output of "altered" or "mutated" potential subdomains that could be present. It saves this output so that it can then be used by your favourite DNS bruteforcing tool.

Alternatively, the -r flag can be passed to altdns so that once this output is generated, the tool can then resolve these subdomains (multi-threaded) and save the results to a file.

Altdns works best with large datasets. Having an initial dataset of 200 or more subdomains should churn out some valid subdomains via the alterations generated.

Installation

You need to clone this repo and run

pip install -r requirements.txt

Usage

# ./altdns.py -i subdomains.txt -o data_output -w words.txt -r -s results_output.txt -d 4.4.4.4,1.1.1.1,8.8.8.8

# ./altdns.py -i subdomains.txt -o data_output -w words.txt -r -s results_output.txt -f resolvers.txt

subdomains.txt contains the known subdomains for an organization
data_output is a file that will contain the massive list of altered and permuted subdomains
words.txt is your list of words that you'd like to permute your current subdomains with (i.e. admin, staging, dev, qa) - one word per line
the -r command resolves each generated, permuted subdomain
the -s command tells altdns where to save the results of the resolved permuted subdomains. results_output.txt will contain the final list of permuted subdomains found that are valid and have a DNS record.
the -t command limits how many threads the resolver will use simultaneously
-d 1.1.1.1,1.0.0.1 overrides the system default DNS resolvers and will use the specified IP addresses separated by , as the resolving server. Setting this to the authoritative DNS server of the target domain may increase resolution performance. (i.e. 9.9.9.9, 1.1.1.1,1.0.0.1)
-f resolvers.txt overrides the system default DNS servers using a list from file.
-v display verboise information about the process
--ip display the ip address associated to any new domain
--update-resolvers update the file resolvers.txt using the updated list from @janmasarik project.

resolvers.txt

Having a DNS servers list could help to increase the resolution performance. @janmasarik has made an excellent job having a working list updated daily.

You can update the list using the built-in flag --update-resolvers or doing a wget request directly.

$ wget https://raw.githubusercontent.com/janmasarik/resolvers/master/resolvers.txt

Screenshots

Show some love

If this tool was useful at all to you during DNS recon stages - we'd love to know. Any suggestions or ideas for this tool are welcome - just tweet @infosec_au or @nnwakelam and we'll work on it.

bp0lr / altdns