Domain_checker application is the trial/demo version for the new EASM (External Attack Surface Management) system called HydrAttack (hydrattack.com), the main idea of which is, based only on the domain name, find almost all of the subdomains and their top 100 open ports
chmod +x domain_checker.sh
./domain_checker.sh
> Enter the domain you want to enumerate
or
bash ./domain_checker.sh
> Enter the domain you want to enumerate
This will work beatifully on Kali but an ultimately universal way is through Docker. Just run
docker build -t domain_checker-image .
docker run -it --rm domain_checker-image