To access the contents of this file, you generally cannot open .003 in isolation. You will need:

: Right-click on the file ending in .001 and select "Extract Here." The software will automatically pull data from .003 to reconstruct the original file.

: The 7z portion signifies the 7-Zip compression format , known for high compression ratios and strong AES-256 encryption.

If you found this file on your system or a shared drive, it likely belongs to a larger backup or a distributed media file.