I have a sql 2008 r2 server and have not setup any maintenance plans. According to the logs it is showing entries like the backups are happening, but why and where are they? It appears to be backing up all databases. In the msdb database backup history it has NT AUTHORITY\SYSTEM as the user performing the backups. Here is part of the logs.
06/17/2013 12:09:52,Backup,Unknown,Database backed up. Database: master<c/> creation date(time): 2013/03/28(18:16:23)<c/> pages dumped: 377<c/> first LSN: 233:139:1<c/> last LSN: 233:141:1<c/> number of dump devices: 1<c/> device information: (FILE=1<c/> TYPE=VIRTUAL_DEVICE: {'{5C438A01-6A88-468A-BE8F-EBB730526E8A}12'}). This is an informational message only. No user action is required.
06/17/2013 12:09:50,spid92,Unknown,I/O was resumed on database master. No user action is required.
06/17/2013 12:09:48,spid92,Unknown,I/O is frozen on database master. No user action is required. However<c/> if I/O is not resumed promptly<c/> you could cancel the backup.
These three events are happening for all databases, everyday at the same time. How can I find out how and why these are happening and where if any place are the backups going?