Boost Security Using Group Managed Service Accounts

Boost security using Group Managed Service Accounts and benefit from the automated way to manage service account credentials. Introduced in Windows Server 2012, Group Managed Service Accounts (gMSAs) enhance security while reducing administrative overhead by automatically handling password management and ensuring seamless authentication across multiple servers.

Key Benefits of Group Managed Service Accounts

1. Automated Password Management: Unlike traditional service accounts, gMSAs automatically generate and update strong passwords without human intervention. This minimizes the risk of password-related security breaches.
2. Simplified Account Administration: gMSAs eliminate the need for manual password resets, reducing administrative workload and ensuring uninterrupted service operations.
3. Enhanced Security:
   -The password is managed by Active Directory (AD) and is not retrievable by users, reducing exposure to credential theft.
   -gMSAs can be used with Kerberos authentication, further strengthening security.
4. Support for Multiple Servers: Unlike regular Managed Service Accounts (MSAs), which are limited to a single machine, gMSAs can be used across multiple servers within an AD domain. This is particularly useful for services running on clusters or load-balanced environments.

Preparing for Group Managed Service Accounts

Before deploying Group Managed Service Accounts (gMSAs) in a Windows environment, certain prerequisites must be met to ensure smooth implementation.

Verify your Active Directory Environment

gMSAs rely on Active Directory (AD) to manage credentials. Ensure that:

• Your domain controllers are running Windows Server 2012 or later
• The Active Directory schema is up to date
• The Key Distribution Service (KDS) Root Key is created

To check if a KDS Root Key exists, run the following Powershell command:

Get-KdsRootKey

If no key is found, create one using this Powershell command:

Add-KdsRootKey -EffectiveImmediately

Note: The key takes 10 hours to become effective by default. If testing in a lab, use:

Add-KdsRootKey -EffectiveTime ((Get-Date).AddHours(-10))

Install the Active Directory PowerShell Module

Ensure that the Active Directory module for PowerShell is installed on the system where you’ll manage gMSAs. You can install it using:

Install-WindowsFeature -Name RSAT-AD-PowerShell

How Group Managed Service Accounts Work

1. Creation: An administrator creates a gMSA in Active Directory using PowerShell.
2. Permissions Assignment: Specific computers or services are granted permission to retrieve and use the gMSA.
3. Automatic Password Rotation: AD automatically updates the password at regular intervals.
4. Service Configuration: Services, such as IIS or SQL Server, are configured to run under the gMSA account.

Create the gMSA Security Group

Group Managed Service Accounts (gMSAs) are designed to be linked with a group of computer accounts that are authorized to retrieve and use them—hence the name Group Managed Service Account.

First of all, we need to create a new security group (“msa-Discover-Group” in the example) in AD by running this Powershell command:

New-ADGroup -Name "msa-Discover-Group" -SamAccountName "msa-Discover-Group" -GroupScope Global -GroupCategory Security

Create the gMSA

To create the actual gMSA, use the New-ADServiceAccount PowerShell command. The following example creates a gMSA named “msa-Discover” for the “JDisc-Internal.local” domain, allowing members of the “msa-Discover-Group” to retrieve its password.

New-ADServiceAccount -Name "msa-Discover" -DNSHostName "JDisc-Internal.local" -PrincipalsAllowedToRetrieveManagedPassword "msa-Discover-Group"

Adding Computer Accounts to the gMSA Security Group

Next, add the computer accounts to the “msa-Discover-Group” security group to grant them access to the gMSA. In the following example, a single computer—the domain controller “WIN-E91R8M04NVC”—is added to the “msa-Discover-Group”.

Add-ADGroupMember -Identity "msa-Discover-Group" -Members "CN=WIN-E91R8M04NVC, OU=Domain Controllers,DC=JDISC-INTERNAL, DC=LOCAL"

Install the gMSA on a Computer

To install and use the gMSA on a computer, run this powershell command:

Install-ADServiceAccount "msa-Discover"

You can now use the gMSA “msa-Discover” to run services, such as the “JDisc Discovery Zero-Footprint Agent”, scheduled tasks, and similar applications.

Use Cases for Group Managed Service Accounts

• Running IIS application pools or the JDisc Discovery Zero-Footprint Agent Service securely
• Managing SQL Server services without manual password updates
• Authenticating services in Active Directory-integrated environments
• Securing Windows Task Scheduler tasks

Conclusion

Managed Group Service Accounts (gMSAs) provide a secure, scalable, and automated solution for managing service accounts in Windows environments. By leveraging gMSAs, you can reduce administrative burden, enhance password security, and improve service reliability without compromising on security best practices  – in essence Boost Security Using Group Managed Service Accounts.