I created a maintenance plan to back up two user databases and system databases over a month ago. I queried the msdb database to view the size of the backups using the following query.
SELECT bs.database_name, bs.type, (bs.backup_size/1024)/1024 [BackupSize (MB)], (bs.compressed_backup_size/1024)/1024 , bs.recovery_model, bf.physical_device_name, bs.user_name, bs.backup_start_date, bs.backup_finish_date FROM msdb..backupset bs INNER JOIN msdb..backupmediafamily bf ON bf.media_set_id=bs.media_set_id
What I saw was, I was able to view the backup set I had created with all the details along with the physical device name. However, there was one more backup set that had all the metrics regarding the backup size, when it was taken etc, but the physical device name had a hexadecimal representation. I verified the sql jobs and maintenance plans and found nothing related to this job. Where else should I find the source of this backup?