Automated file rippers, conversion scripts, or peer-to-peer file sharing networks sometimes glitch and append duplicate extensions during automated processing cycles.
Even if this specific file is just a poorly named video rather than a virus, its structure indicates severe handling issues: JULIE.mp4.mkv.mp4
If you downloaded a file from an untrusted source, right-click it and run a scan with your antivirus software before double-clicking it. Automated file rippers
To ensure you do not fall victim to disguised malicious files, adopt these standard security habits: the user only sees GreatVideo.mp4 .
Go to your operating system folder settings and uncheck the option that says "Hide extensions for known file types." This ensures you always see the actual final extension.
Because Windows might hide the .exe extension, the user only sees GreatVideo.mp4 .