Strange error.log entry and digital ocean ubuntu pwnage script

I found a strange entry in my nginx error log file:

2014/06/29 18:05:17 [crit] 878#0: *31 connect() to unix:/var/run/php5-fpm.sock failed (13: Permission denied) while connecting to upstream, client: 107.170.53.191, server: localhost, request: "GET /wp-admin/install.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "192.81.217.36"

I have a couple of WP installs in this New York based cloudlet. I cannot fully understand this log entry, so I went to check this IP address (107.170.53.191). Apparently it is hosted at the same datacenter, but it shows the default Apache page (It works!).

It also has some WP files or something that look like a WP install. I went looking in the wp-content/uploads folder, which I know lists the files in a default install. It has some weird .so files and a script called pwn.ssh that my curiosity made me download to take a look.

This file has a comments saying it is a ‘Digital Ocean [Ubuntu x86_64] pwnage script’. (It is located at http://107.170.53.191/wp-content/uploads/2014/06/ocean/).

So, my questions are:

1. Is this a compromised system or a droplet set up to gain access to other droplets?
2. Should I be worried?
3. Should I warn Digital Ocean staff? How to?