Historic broadcasts or educational videos preserved by digital libraries.

Personal or communal data archives that have been indexed by search engines. Safety First: The Risks of "Free" Archive Downloads

Ensure the file ends in .mp4 and not .exe or .zip.exe .

In the world of data management, strings like "fhdjufe568" usually serve one of three purposes:

Unique codes used to verify that a file hasn't been corrupted or altered.

If you are unsure about the file's origin, open it in a virtual machine or a dedicated sandbox environment. How to Properly Search for Archived MP4s