subfinder

Subdomain discovery tool that discovers valid subdomains for websites

SubFinder is a subdomain discovery tool that discovers valid subdomains for websites by using passive online sources. It has a simple modular architecture and has been aimed as a successor to sublist3r project. SubFinder uses Passive Sources, Search Engines, Pastebins, Internet Archives, etc to find subdomains and then it uses a permutation module inspired by altdns to generate permutations and resolve them quickly using a powerful bruteforcing engine. It can also perform plain bruteforce if needed. The tool is highly customizable, and the code is built with a modular approach in mind making it easy to add functionalities and remove errors.