Subdomain Takeover is pwning the subdomain of the target website. It is
1. Enumeration methodology:
Getting subdomain with tools or some online services.
2. Recon methodology:
Checking for existence of vulnerability with tools or manually.
3. Exploit methodology:
Go to respective third party host website and follow method of respective sites to pwn the subdomain.
1. sublist3r: https://github.com/aboul3la/Sublist3r
2. knockpy: https://github.com/guelfoweb/knock
3. Amass: https://github.com/OWASP/Amass