Use a tool like MediaInfo to see the "Original Source Name" often stored in the header tags.
In some cases, double extensions are used by malware to hide the true file type (e.g., file.mp4.exe ). However, since both .mkv and .mp4 are video containers, this is more likely a clerical or automated naming artifact. Numerical Prefix ("11693") 11693.mkv.mp4
A temporary file generated by a server-side transcoder (like those used by YouTube, Vimeo, or private clouds). Use a tool like MediaInfo to see the
Many surveillance systems export clips using sequential numbering rather than timestamps. file.mp4.exe ). However