If you received this file from an unknown source or a suspicious channel, exercise caution: What are MOV files? - Adobe
If you are seeing a file with this name, it is important to understand how Telegram handles such files and the potential risks involved: Understanding the File and Format
: Users on platforms like the Raspberry Pi Forums have noted that Telegram Desktop sometimes saves downloaded videos with generic or "strange" names ending in .mov rather than their original name or format.