: Use a tool like MediaInfo to see the technical details (encoding date, software used) which might hint at its origin.

Since the filename itself doesn't describe the video, you can try the following to figure out what it is:

This filename appears to be an automatically generated string, common for files uploaded to or downloaded from messaging platforms like . The "AgAD..." prefix is a standard format used by Telegram's servers to identify unique media objects. What is this file?

: Open the file in a media player like VLC and go to Tools > Media Information to see if there is a title or description embedded in the metadata.