Microsoft Entra ID (MEID) integrates with on-premises Active Directory (AD) using either "Microsoft Entra Connect Sync" or "Microsoft Entra Cloud Sync". This integration enables unified user identities across hybrid environments and supports various device join types to provide flexible management of user access and authentication.
It is important to consider the resources synchronized with MEID from a local perspective because this could potentially enable the compromise of the on-premises AD environment from the cloud Entra ID.
To mitigate risks when synchronizing on-premises Active Directory with Microsoft Entra ID, limit synchronized data to essential attributes and objects only.
Integrate on-premises Active Directory domains with Microsoft Entra ID
Install the Microsoft Entra provisioning agent
Microsoft Entra Connect Sync service features
User Hard Matching and Soft Matching in Azure AD Connect
Microsoft Entra registered devices
Name: Hybrid Entra ID Information
Codename: C-AAD-INFORMATIVE
Severity: Low
Dr. Nestori Syynimaa: AADInternals