In a ransomware disaster recovery situation, we have a physical server that we are trying to recover by rebuilding the physical server, installing a new instance of SQL Server (SQL 2012 Enterprise SP 4), and restoring all database file storage drives from file system backups. That should work for all user databases, but what about master?
Will the new instance of SQL start successfully if we replace master mdf and ldf files from the last good copy?
If that isn't possible, can the old master database files be attached as a user database to access metadata like logins, linked servers, server level permissions? The system views like sys.server_principals won't work, so the underlying metadata tables will have to be accessed directly. Is this doable?
(We may have a master database backup file we can restore from, if so that is Plan A. I'm trying to define Plan B and Plan C. While infrastructure folks are bringing back the network and sorting out what can be recovered from what must be rebuilt, management has little to do but request more spreadsheets.)