Horror Movie Involving a Trip to a “Haunted” Mansion

Spoilers for whatever this movie may be:
Around mid/late-2017, I remember watching a movie with an animated opening credits sequence. The rest of the movie continued as live action. It had that setup reminiscent of “House on Haunted Hill”, wherein a group of (possibly students, this time) show up to a mansion. A hairy “monster” starts killing them off, but the monster is revealed to be one of two the students working together dressed up as the monster. They chase down the final (?) character and pull out machine guns as they reveal through some dialogue they were spies all along.

I think it was an indie movie, looked kind of low-budget but had some production value to make me think it was released after 2000 (more likely 2010-2017). The spies might have been Russian/Soviet, and since older movies would have tended to play that sort of thing up a little more, I question if it was for sure released after 2000. It seems like it had a simple title, possibly with “the” in it. The movie might have been non-American/non-English.
It seems like someone would remember this movie, but I can’t seem find it anywhere. Please help?
(Movies it isn’t: Hausu, House, House 2, You’re Next, The Invitation, or Le Manoir. Discovered it mentioned in a reddit looking for movies like Coherence, for which it seems to only thematically share “low-budget house…thing”.)