First of all, this is a shitty copy-paste post which dosent make any sense. But as far as I can see, this just searches for various functions and variables that are often incorrectly used (leading to vulnerabilities). I dont see the point in this.. If you already have a shell on the server, why would you want to find more vulnerabilities? And if this is a non-malicious shell, why would it be... Coded in PHP in the first place, or at least why not CLI? I mean this could be done with one line of bash.