Apparently, some Russian special editions of Call of Duty Black Ops II shipped with the soundtrack on 2 physical CDs.
Apparently, somebody ripped those CDs to FLAC files.
This was found on a private torrent tracker. I can't vouch for it's authenticity, except to say that I've done a spectral analysis of it in Adobe Audition myself, and it seems like the real deal. I've listened to it on a decent stereo, and in decent headphones, and some of the compression artifacts I noticed on the official mp3 release are gone, so I ditched my mp3s in favor of this.
Of course, that'd be the opinion of an anonymous stranger, but hey, there are few guarantees in life, right?