The DefaultAccount, also known as the Default System Managed Account (DSMA), is a built-in account introduced in Windows 10 version 1607 and Windows Server 2016. The DSMA is a well-known user account type. It is a user neutral account that can be used to run processes that are either multi-user aware or user-agnostic. The DSMA is disabled by default on the desktop SKUs (full windows SKUs) and WS 2016 with the Desktop. (from Technet)
If the domain was created with domain controllers that run Windows Server 2016, the DefaultAccount will exist on all domain controllers in the domain. If the domain was created with domain controllers that run an earlier version of Windows Server, the DefaultAccount will be created after the PDC Emulator role is transferred to a domain controller that runs Windows Server 2016. The DefaultAccount will then be replicated to all other domain controllers in the domain.
