AZ-800 Administering Windows Server Hybrid Core Infrastructure Exam

Implement service accounts

Configure and Secure Service Account Identities

When running Windows services in a hybrid Azure environment, you use service accounts to let services authenticate without manually handling passwords. Microsoft offers Managed Service Accounts (MSAs) in Active Directory to automate credential management and simplify SPN updates. Two main types are available: Standalone MSAs (sMSAs) for single servers and Group MSAs (gMSAs) for multiple hosts. Using MSAs in Azure VMs joined to Azure AD DS helps protect service identities and reduces the risk of leaked credentials.

Standalone Managed Service Accounts (sMSAs) are tied to one server and handle all password and SPN tasks automatically. They offer automatic password rotation, updating complex 240-byte passwords every 30 days to block brute-force attacks. Additional advantages include:

• Simplified SPN management: Windows updates service principal names when configurations change.
• High security: Uses lengthy, randomized passwords to prevent credential guessing.
• Clear auditing: Assign each service its own sMSA to track actions precisely.

Group Managed Service Accounts (gMSAs) extend credential automation to server farms and scale sets in Azure. They also enable automatic password management, ensuring each host uses the same secure credentials. Key benefits include:

• Multi-server support: Deploy one gMSA across all servers running a service.
• Centralized SPN control: Configure service principal names with PowerShell or Azure AD DS tools.
• Load balancing ready: Ideal for clusters, since every machine can authenticate with identical credentials.

In a hybrid deployment, apply a clear process to set up service accounts. Use the following steps:

• Select the right account type: choose gMSA for multi-host scenarios and sMSA for single-server cases.
• Activate automatic password management: trust Windows or Azure AD DS to rotate credentials.
• Set up service principal names (SPNs): use PowerShell cmdlets like Set-ADServiceAccount or Azure tools.
• Grant least-privilege permissions: restrict each account to only the rights it needs.
  Following these steps helps reduce configuration errors and keeps credentials consistent across environments.

For stronger protection, adopt security best practices around service accounts. Focus on:

• Least-privilege enforcement: limit account rights to the bare essentials.
• Regular audits: review logs and permissions to find and fix issues.
• Fallback to user-managed accounts: if MSAs aren’t an option, enforce strict password policies and routine changes.
  By applying these practices, you lower the attack surface and ensure service identities remain well-protected.

Conclusion

In summary, Managed Service Accounts—with sMSAs for single servers and gMSAs for clusters—streamline password and SPN management in hybrid Azure deployments. Implementing them means choosing the correct type, enabling automated rotations, and registering SPNs accurately. Coupled with least-privilege permissions and regular audits, this approach minimizes manual errors and strengthens the security of Windows services.