If you are unable to open the file due to the unusual extension:

Uploads to Google Photos or OneDrive where the original metadata is preserved in the title.

This specific naming pattern is characteristic of Samsung Galaxy or other Android smartphones . Unlike iPhones (which typically use "IMG_xxxx"), these devices generate filenames based on the exact second the recording started.

Open the file using the VLC Media Player , which can often read video data even if the file extension is corrupted or non-standard.