Maintaining Privileged Account Hygiene: The Critical Role of Semi-Privileged User Group Management

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In today’s complex Active Directory environments, maintaining proper privilege separation and access control is not just a best practice—it’s a security imperative. The principle of least privilege demands that administrative accounts should only have the minimum permissions necessary to perform their designated functions. However, in practice, semi-privileged accounts often accumulate unnecessary group memberships over time, creating potential security vulnerabilities and compliance issues.

The Challenge of Privilege Creep

Privilege creep is a common phenomenon in enterprise environments where user accounts gradually accumulate permissions over time. This is particularly problematic with semi-privileged accounts (often designated as Tier 0, Tier 1, and Tier 2 administrators) that are meant to operate within specific administrative boundaries. When these accounts gain membership in non-administrative groups, they can:

  • Bypass security controls designed for the tiered administration model
  • Increase attack surface by providing additional access paths for malicious actors
  • Violate compliance requirements such as PCI DSS, SOX, or HIPAA
  • Compromise the integrity of the administrative tier structure

Understanding the Active Directory Delegation Model

Microsoft’s recommended approach to Active Directory security follows a tiered administrative model:

Tier 0 (Control Plane)

  • Scope: Domain controllers, domain admin accounts, enterprise admin accounts
  • Purpose: Manages the AD forest and domain infrastructure
  • Risk Level: Highest – compromise affects entire forest

Tier 1 (Management Plane)

  • Scope: Member servers, server administrators, application administrators
  • Purpose: Manages server infrastructure and enterprise applications
  • Risk Level: Medium – compromise affects server infrastructure

Tier 2 (Data/User Plane)

  • Scope: Workstations, end-user accounts, help desk administrators
  • Purpose: Manages user accounts and workstation infrastructure
  • Risk Level: Lower – compromise affects user productivity

The key principle is that higher tiers should never authenticate to lower tiers, and administrative accounts should only be members of groups within their designated tier.

Real-World Scenarios: When Group Hygiene Matters

Scenario 1: The Compromised Service Account

Situation: A Tier 1 server administrator account (SVC_T1_SQLAdmin) was inadvertently added to a user group (CN=All Users,OU=Groups,DC=company,DC=com) during a bulk operation.

Risk: An attacker who compromises this service account now has access to user resources that should be completely separate from server administration.

Solution: Regular execution of group hygiene maintenance identifies and removes such inappropriate memberships.

Scenario 2: The Audit Failure

Situation: During a compliance audit, auditors discovered that multiple Tier 0 accounts were members of various non-administrative groups across the organization.

Risk: Potential compliance violations and failed audit findings that could result in fines or loss of certifications.

Solution: Automated group hygiene processes ensure continuous compliance with the tiered administration model.

Scenario 3: The Lateral Movement Attack

Situation: An attacker gained access to a Tier 2 administrator account that had accumulated permissions in multiple non-administrative groups over time.

Risk: The attacker can use these additional permissions to move laterally across the network, accessing resources that should be outside the scope of a Tier 2 administrator.

Solution: Regular group membership cleanup limits the attack surface and contains potential breaches.

The Technical Solution: Automated Group Hygiene

The Set-NonPrivilegedGroupHousekeeping function from the EguibarIT.HousekeepingPS module provides an automated solution to this critical security challenge. Here’s how it works:

Key Features:

  1. Targeted Scope: Focuses on semi-privileged accounts within designated administrative OUs
  2. Intelligent Filtering: Preserves legitimate administrative group memberships while removing non-compliant ones
  3. Safe Operation: Includes comprehensive validation and ShouldProcess support for testing
  4. Comprehensive Logging: Provides detailed verbose output for audit and troubleshooting purposes

Implementation Example:

Best Practices for Implementation

1. Regular Schedule

Execute group hygiene maintenance on a regular schedule (weekly or bi-weekly) to prevent privilege creep accumulation.

2. Integration with Change Management

Incorporate group hygiene checks into your change management process to catch unauthorized modifications quickly.

3. Monitoring and Alerting

Implement monitoring to alert when administrative accounts are added to non-administrative groups outside of approved processes.

4. Documentation and Training

Ensure your team understands the importance of the tiered administration model and the risks of inappropriate group memberships.

The EguibarIT.HousekeepingPS Module

The Set-NonPrivilegedGroupHousekeeping function is part of the comprehensive EguibarIT.HousekeepingPS PowerShell module, which provides a suite of tools for maintaining Active Directory security and compliance. The module includes functions for:

  • Permission delegation following the tiered administration model
  • Group membership management and cleanup
  • Security validation and compliance checking
  • Automated housekeeping tasks for large-scale environments

Key Advantages:

  • Enterprise-Ready: Designed for environments with 100,000+ objects
  • Security-First: Implements Microsoft’s recommended security practices
  • Comprehensive: Covers multiple aspects of AD security and maintenance
  • Well-Tested: Includes comprehensive Pester test coverage
  • Community-Driven: Open source with active community support

External References and Further Reading

  1. Microsoft Security Best Practices:
  2. NIST Cybersecurity Framework:
  3. Industry Standards:
  4. Microsoft Documentation:

Conclusion and Call to Action

Maintaining proper privilege separation in Active Directory is not a one-time task but an ongoing process that requires dedicated attention and the right tools. The Set-NonPrivilegedGroupHousekeeping function provides an automated solution to one of the most common privilege management challenges in enterprise environments.

Get Involved

The EguibarIT.HousekeepingPS module is an open-source project that benefits from community contributions. Whether you’re a security professional, system administrator, or PowerShell enthusiast, your contributions can help improve Active Directory security for organizations worldwide.

How to contribute:

  • Visit the repository: https://github.com/vreguibar/EguibarIT.HousekeepingPS
  • Report issues: Found a bug or have a feature request? Open an issue
  • Submit pull requests: Improve existing functions or add new capabilities
  • Share experiences: Help others by sharing your implementation stories
  • Provide feedback: Your real-world usage helps improve the module

Getting Started

  1. Install the module: Available from the PowerShell Gallery
  2. Review the documentation: Comprehensive help is available for all functions
  3. Start with -WhatIf: Test all operations before executing in production
  4. Join the community: Connect with other users and contributors

Remember: Security is everyone’s responsibility, and maintaining proper privilege separation is a critical component of a robust cybersecurity strategy. Start implementing regular group hygiene maintenance today to protect your organization from the risks of privilege creep and ensure compliance with security best practices.

The EguibarIT.HousekeepingPS module represents years of real-world experience in managing large-scale Active Directory environments. By contributing to this project, you’re helping build better security tools for the entire community.