Enhancing Privileged Account Security: Authentication Policies and Silos (2023)

In the realm of cybersecurity, safeguarding privileged accounts against credential theft is paramount. One robust strategy to fortify administrative accounts involves the adept use of Authentication Policies and Silos, as advocated by Microsoft. This article delves into a step-by-step guide on implementing these security measures, drawing insights from the best practices employed by Lab.dz.

Understanding Authentication Policy Silos

Authentication policy silos are a mechanism to confine high-privilege credentials, ensuring they are accessible only to designated users, computers, or services. Lab.dz exemplifies this approach by adhering to Microsoft's tiering model, where T0 Admins utilize dedicated administrative workstations to access T0 Servers.

Scenario Overview

Lab.dz's environment comprises a domain controller (DC01), two member servers (MEM01 and MEM02), and client computers. Notably, domain admins, represented by Amine and Mehdi, use a dedicated administrative workstation named PAW0 to access domain controllers.

Implementation Steps

1. Preparing the Domain

1. Confirm the domain Functional level is 2012 R2 or higher (Lab.dz uses 2016).
2. Configure domain controllers (KDC) to support claims, compound authentication, and Kerberos armoring.

2. Configuring Client Computers

1. Enable the Kerberos client support for claims, compound authentication, and Kerberos armoring.

3. Authentication Policy and Silo Setup

1. Open the Active Directory Administrative Center.
2. Create a new authentication policy, ensuring to enforce policy restrictions.
3. Configure user sign-on settings, optionally adjusting TGT lifetime.
4. Create an authentication policy silo, specifying permitted accounts and associating the authentication policy.

4. Assigning Policies

1. Assign the created policies to relevant accounts (e.g., DC01, PAW0, Amine, Mehdi).

5. Verification and Troubleshooting

1. Restart computers within the silo to ensure re-authentication.
2. Enable relevant logs for troubleshooting, such as AuthenticationPolicyFailures-DomainController.
3. Utilize Advanced Audit Policy Configuration for enhanced visibility into user and device claims.

Troubleshooting Insights

Troubleshooting is facilitated by enabling specific logs, such as AuthenticationPolicyFailures-DomainController. Additionally, gaining visibility into user and device claims through Advanced Audit Policy Configuration proves invaluable.

Conclusion: A Robust Defense

Authentication policy and silos emerge as formidable tools in preventing high-privilege accounts from unauthorized usage on insecure computers. This proactive approach, exemplified by Lab.dz, not only strengthens security but also aligns with best practices in the cybersecurity domain.

In conclusion, safeguarding privileged accounts requires a multifaceted approach, and implementing authentication policies and silos stands out as a cornerstone in this endeavor. By following Lab.dz's lead, organizations can fortify their security posture and mitigate the risks associated with credential theft.