5857 (3).mp4 -

Because the name is generic, the content could be anything from a personal video to a saved meme. To identify what's inside, you can:

: Many DVR systems use four-digit numbering for short recorded segments. 5857 (3).mp4

Are you trying to this file, or did you find it on a shared drive ? Because the name is generic, the content could

: Use a tool like MediaInfo to see if there are encoded tags or a "Writing Library" that reveals the app used to create it. Because the name is generic