Check where the file was saved. Different naming conventions can hint at the origin:
If found in a "Temp" or "Cache" folder, it may be a fragment from a site you visited recently. 2. Search for the Content video-6b1793db763207856af8e11bf5b4bf16-V.mp4
If you want to know what the video contains without playing it (or if you can't open it), you can: Check where the file was saved