Shelliphant gives you a website where you can run system level commands and view their output as a webpage. This is meant for personal use only.
Upload it to any Apache or Nginx server that can render PHP. You get access to a very simple shell like input where you can run system level commands.
Obviously, I do not condone hacking/stealing data but I also can't force you not to. Anyways, this script is free to download and use as you want. I deny any and all responsibility for any damages it can cause directly or indirectly.