Malicious software often uses double extensions or hides as media files to trick users into running executable code.
MP4 (MPEG-4 Part 14) is a container format that stores video, audio, subtitles, and images. Virtts.mp4
The file could be a standard MP4 that has been converted or is intended for use with VR video converters to be viewed in 180° or 360° immersive formats. Malicious software often uses double extensions or hides