If you’re in the hosting business for a while, you start to see your fair share of PHP exploit code. Code that’s been uploaded through a CMS exploit, and then used to further exploit others: attack other servers, send spammails, …
There’s now a github repo where I “collect” these exploit scripts that have been uploaded: PHP Exploit Scripts. It also includes this README file, which pretty much sums it up.
Why do you put these online? They're dangerous! Yes, obviously. Don't copy them and store them on your own server. These are scripts found on hacked systems, so they're used to exploit the server and abuse some kind of vulnerability. They are indeed dangerous in themselves. But if anyone can exploit a server or CMS, they can upload far more dangerous tools than these PHP scripts.
This repo does not contain any info or guides on how those files have been uploaded or what exploit on the CMS was being used. This is merely the result: what does an “attacker” do, what files do they upload, once they have found a method of copying PHP code to the remote server.
Interested? Have a look at the Github repo: mattiasgeniar/php-exploit-scripts.