Subscan is a simple tool for subdomain scanner, it can scan subdomains fast.
git clone https://github.com/zidansec/subscan.git
cd subscan
./subscan exemple.com
Or
sudo wget https://raw.githubusercontent.com/zidansec/subscan/master/subscan -O /bin/subscan && sudo chmod +x /bin/subscan
subscan exemple.com