Information
Password hash synchronization is one of the sign-in methods used to accomplish hybrid identity synchronization. Microsoft Entra Connect synchronizes a hash, of the hash, of a user's password from an on-premises Active Directory instance to a cloud-based Entra ID instance.
Note: Audit and remediation procedures in this recommendation only apply to Microsoft 365 tenants operating in a hybrid configuration using Entra Connect sync, and does not apply to federated domains.
Password hash synchronization helps by reducing the number of passwords your users need to maintain to just one and enables leaked credential detection for your hybrid accounts. Leaked credential protection is leveraged through Entra ID Protection and is a subset of that feature which can help identify if an organization's user account passwords have appeared on the dark web or public spaces.
Using other options for your directory synchronization may be less resilient as Microsoft can still process sign-ins to 365 with Hash Sync even if a network connection to your on-premises environment is not available.
Solution
To remediate using the on-prem Microsoft Entra Connect tool:
- Log in to the on premises server that hosts the Microsoft Entra Connect tool
- Double-click the Azure AD Connect icon that was created on the desktop
- Click Configure
- On the Additional tasks page, select Customize synchronization options and click Next
- Enter the username and password for your global administrator.
- On the Connect your directories screen, click Next
- On the Domain and OU filtering screen, click Next
- On the Optional features screen, check Password hash synchronization and click Next
- On the Ready to configure screen click Configure
- Once the configuration completes, click Exit
Impact:
Compliance or regulatory restrictions may exist, depending on the organization's business sector, that preclude hashed versions of passwords from being securely transmitted to cloud data centers.