It may look like a video file (MP4), but it could actually be an executable script (like .exe or .scr ) hiding behind a double extension (e.g., newly.mp4.exe ).
On Windows, go to Folder Options and uncheck "Hide extensions for known file types." This reveals if the file is actually newly.mp4.exe . newly .mp4
If you’re curious but want to stay safe, upload the suspicious file to VirusTotal to see if dozens of different antivirus engines recognize it as a threat. It may look like a video file (MP4),