Dark Ambience Soundscapes
This is the Ambience pack (1-8) by yewbic of freesound. They allowed use under CC-BY-SA 3.0 on their profile page. ("I permit usage of all my sounds, including my ambience sounds, http://www.freesound.org/packsViewSingle.php?id=2122 under terms of Creative Commons Attribution ShareAlike 3.0 license")
The ambient tracks are 20-50 seconds long each.
8 wav files. The preview plays 5 seconds of each track (s5-s10).
Useful for background and more.