: Run it through an antivirus program or upload it to VirusTotal before opening.
Could you share or its file size ? That would help narrow down exactly what "762777" refers to. How to play MP4 files in Windows - Microsoft Support 762777.mp4
: Right-click the file and select Properties (Windows) or Get Info (Mac) to see the file size, resolution, and creation date. Common Contexts : : Run it through an antivirus program or
: Most modern operating systems can open .mp4 files by double-clicking them. Windows : Use Windows Media Player or the Movies & TV app. How to play MP4 files in Windows -
The file appears to be a generic video file, likely a temporary download name or a specific asset from a game or educational software. Without more context on where you found it, How to Open the File