You can find more here:
https://www.exploit-db.com/google-hacking-database/ These are called "Google Dorks" for some reason, even though there's nothing dorky about them. Some of these are honeypots / tarpits monitoring inbound traffic, others are actual servers which are running old versions of PHP. Frankly though if it's public like that it often is a red flag that the webmaster has made other bad choices with their servers...