I texted my friend from Belarus to make sure, I'll update once I get the answer
"major_brand: mp42
user_defined_text: (compatible_brands) isommp423gp5my guess is OP had a music disc (ISOM) and used a program to rip the audio from the disc to mp4. If OP still the iso maybe we could get some answers there.
https://app.box.com/s/9erwiqjvq4xtx9hwd6xyDo you still have the original file? Perhaps some metadata on it could be useful, an exact date could be inside the metadata
Katy
1500 days ago