Never heard that kind of file..Anyway, try to check the metadata inside that file, search md5sum hash file on internet. Maybe you can get something..
-- Email : Robbi Nespu <robbinespu AT SPAMFREE gmail DOT com> PGP fingerprint : D311 B5FF EEE6 0BE8 9C91 FA9E 0C81 FA30 3B3A 80BA PGP key : https://keybase.io/robbinespu/pgp_keys.asc