These are errors in the statistics blobs for the database EPICSYS (some of their pages are marked as allocated in two IAM pages for two objects) and you're not going to be able to fix this with CHECKDB. From what you've said about your backups, your choices are:

1) use DBCC PAGE to try to figure out which tables in the database are affected and drop their statistics

2) extract all data out into a new database

Unless you're really comfortable using DBCC PAGE I would recommend option #2.

Thanks