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Red Teaming

Understanding and Enumerating Restricted Groups in Active Directory

fuffsec

• 1 min read

Introduction

Active Directory (AD) is a cornerstone for managing permissions and resources in many organizations. Within AD, the concept of "restricted groups" is vital for maintaining security and access controls. This blog will explore what restricted groups are, their importance in AD security, and how to test and evaluate these groups using PowerView commands.

What Are Restricted Groups?

Restricted groups in AD are a security feature that ensures certain groups maintain a specific membership. This setting can enforce strict adherence to predefined group memberships, which is critical for roles requiring elevated privileges, such as administrative accounts. The primary objective of restricted groups is to prevent unauthorized changes and ensure that only approved users have access to sensitive systems and data.

Importance of Restricted Groups

  1. Security Enforcement: Ensures that only authorized personnel have access to sensitive data and systems.
  2. Compliance: Helps in adhering to compliance standards by ensuring consistent group memberships.
  3. Risk Mitigation: Reduces the risk of privilege escalation attacks by controlling administrative access.

Pentesting Restricted Groups

Pentesting restricted groups involves identifying and analyzing these groups to ensure they are properly configured and secure. PowerView, a powerful PowerShell tool, can be used to enumerate and test these groups effectively.

Key PowerView Commands for Pentesting Restricted Groups

  1. Get-DomainGPOLocalGroup
    1. Returns all GPOs in a domain that modify local group memberships through 'Restricted Groups' or Group Policy preferences. Also return their user membership mappings, if they exist.
  2. Get-DomainGroupMember
    1. Get all the members of the restricted group
  3. Invoke-ACLScanner
    1. This command scans the domain for objects with potentially interesting ACLs (Access Control Lists) set.

Conclusion

Understanding and testing restricted groups in AD is crucial for maintaining a secure environment. By leveraging PowerView commands, security professionals can effectively audit and ensure that restricted groups are correctly configured and enforced. Regular audits and pentesting of these groups can help prevent unauthorized access and strengthen the overall security posture of the organization.