How are database backups conducted using SQL Server VSS Writer Service
You will need to identify the Backup strategy which would be using the VSS Writers for taking backups/Restore.

In our environment we had Netbackup and HPDP (Data Protector). While for Netbackup the location would be the master media location ,for HPDP it used to be similar to what you have {922DDBA9-0686-46B8-94BC-XXXXXXXXXX}.

HPDP uses VSS Writers for the backups and it is what was in our case. It can differ in your situation but there is some backup agent which is takin it.