Well, I don't know if it is this or not... but all I DO know is there is no way in Hades would you catch me running anything from this "person" on any site I owned.
Also, do a template search for v1.js and see if anything comes up.
When you ping cav.finalcdn.net the IP returns as 18.104.22.168.
Doing a whois on that IP comes back to an OVH server. When you go to that IP in a browser, it is a site called Trust.Plus, which apparently has a XenForo add-on integration that deals with "bad registrations".