Randomly numbered files can sometimes be suspicious. Before double-clicking, run a quick check:
If the file won't open, you can try "transcoding" it. Drop 39263.mp4 into Handbrake and convert it to a standard "Web Optimized" preset. 39263mp4
Sometimes the easiest way to check a file is to drag it directly into a Chrome or Firefox tab. 3. Safety First: Is it a Virus? Randomly numbered files can sometimes be suspicious
Let us know in the comments, and we can help you decode where they might have come from! 39263mp4