If you downloaded this file from an untrusted source or an unexpected email attachment, do not open it. Randomly named .mp4 files can sometimes be used to deliver malware through vulnerabilities in outdated media players.
Open the file using a universal player like VLC Media Player , which can handle almost any .mp4 encoding and show you technical information about the video codec used. 22601mp4
Right-click the file and select Properties (Windows) or Get Info (Mac). Look at the "Details" or "General" tab for the creation date and the "Origin" section to see which software created it. If you downloaded this file from an untrusted