Sometimes automated "video downloader" extensions save files with generic titles and a number in parentheses if multiple files are grabbed at once.
Attackers name files using popular search terms or suggestive themes to trick users into downloading and opening them. Hot Girls (51) mp4
Check if the file is actually named something like Hot Girls (51).mp4.exe . Windows often hides known file extensions, making an executable application look like a video file. Hot Girls (51) mp4
A standard .mp4 video is usually several megabytes to gigabytes. If the file is very small (e.g., under 1MB), it is likely a script or a shortcut, not a video. Hot Girls (51) mp4
Open the file inside a virtual machine or a tool like Windows Sandbox which isolates the file from your actual operating system.