Is XYZ in the address?

So, sometimes when I click on certain threads, it opens up this weirdly formatted URL like:
Like this:

The thing is, even though I'm not logged in at all on this .xyz site, I can still read the thread just fine... but I can't actually sign in or anything?
Is this just some glitch with the main US forum, or am I looking at a keylogger or some other malware on my machine?

Wait, is the entire Reddit site just mirrored at that URL? What on earth...