How exactly backups are executed by SQL Server VSS Writer Service

We have few servers running backups from unknown sources. The physical_device_name in the backupmediafamily table is approximately {922DDBA9-0686-46B8-94BC-XXXXXXXXXX} 2.

Once I checked, I saw that this kind of backup was running in the database. So I quit the SQL Server VSS Writer service and the backup stopped. I had to think that backups are done by this service. I'm still unaware of how Windows / SQL should trigger this backup at any given time, because the SQL Server VSS Writer service is running 24 * 7.

I also saw a scenario on some servers running SQL Server VSS Writer, but these backups do not take place in SQL.

Can someone help me determine exactly what causes SQL Server to trigger such backups because I want to stop such backups across the enterprise.