This showed up in r/deepintoyoutube:
https://www.youtube.com/watch?v=j1ExfbH4Jew
I've posted it around, and no one has solved it. I believe it is a cipher for a couple of reasons, at the end 26 unique letters are listed (could be arranged as a key?), and the numbers listed throughout the video are numbered 1-26. I don't think it is standard Caesar cipher. Here is what I know:
The numbers listed in the video are:
1 18 10 10 2 20 9 10 10 17 24 5 15 10 6 17 26 16 22 5 25 17 6 12 23 23 2 10 14 22 14 10 6 11 12 5 10 17 10 12 26
followed by these letters at the end: tgnauhobvipcwjqdxkreylsfzm
I put the video on slow and did some research. The video is shot in Sydney, Nova Scotia, Canada. First I noticed a Canadian Diabetes donation center, and a flag. Then I saw the word Mayflower Mall at the fair grounds. Looked up mayflower flower mall, found that it was located in Sydney. Also I confirmed this by googling the Hampton in that shows up in very short clips in the film. Same hotel, you can also see the grounds of the hotel show up in several shots.
If you slow down the video you can see a scary clown twice. Once at the end, standing at the end of a dark hallway holding a knife, and another time you can briefly see the same gown the clown is wearing hanging up.
View this post for some ideas from other people:
https://www.reddit.com/r/codes/comments/6nq3df/creepy_video_found_on_a_usb_with_a_mysterious/