This tool can gather possible subdomains and identify live hosts
To run this tool need to install following tools
sudo apt install sublist3r
sudo apt install amass
sudo apt install golang
nano ~/.bashrc
export PATH=$PATH:/usr/local/go/bin
export GOPATH=$HOME/go
export PATH=$PATH:$GOPATH/bin
go get -u github.com/tomnomnom/anew
go get -u github.com/tomnomnom/assetfinder
go get -u github.com/jaeles-project/gospider
go get -u github.com/tomnomnom/httprobe
git clone https://github.com/geeksniper/subdofind.git
cd /subdofind
chmod +x subdofind.sh
./subdofind.sh <domain_name>