Active Directory Security Assessment Guide

Introduction

Active Directory (AD) serves as the identity backbone of most enterprise environments, providing centralized authentication, authorization, and access management for users, devices, applications, and services. Because Active Directory is often the primary source of trust within an organization, security weaknesses can lead to widespread compromise across systems, domains, and forests. This guide provides a structured approach to assessing the security of an Active Directory environment and identifying opportunities for hardening and risk reduction.

Assessment Objectives

The primary objectives of an Active Directory security assessment are to:

Evaluate the security posture of the Active Directory environment
Identify misconfigurations and excessive privileges
Discover attack paths that could lead to domain compromise
Assess identity and access management controls
Evaluate Active Directory Certificate Services (AD CS)
Review logging, monitoring, and detection capabilities
Provide actionable remediation recommendations
Reduce opportunities for privilege escalation and lateral movement

Why Active Directory is a High-Value Target

Active Directory is often considered the most critical asset within internal enterprise networks.

Key Reasons

Centralized Authentication

Almost every user, workstation, server, and application relies on Active Directory authentication.

High Privilege Concentration

Privileged users and service accounts often provide extensive access across multiple systems.

Trust Relationships

Compromise can extend beyond a single domain through domain and forest trust relationships.

Identity-Centric Attacks

Modern attackers frequently target identities rather than systems.

Security Risks

Excessive permissions
Weak service-account configurations
Credential theft
Delegation abuse
Misconfigured trusts
AD CS vulnerabilities
Weak monitoring controls

Active Directory Security Assessment Methodology

Phase 1: Active Directory Reconnaissance & Enumeration

Objective

Understand the structure of the Active Directory environment and identify potential attack paths.

Assessment Areas

Domain Information

Review:

Forest structure
Domain structure
Domain Controllers
Sites and Services
Trust relationships

User Assessment

Identify:

Disabled accounts
Dormant accounts
Service accounts
Administrative accounts
Shared accounts

Group Assessment

Review membership of:

Domain Admins
Enterprise Admins
Schema Admins
Account Operators
Backup Operators
Server Operators

Privilege Mapping

Identify:

Excessive permissions
Nested privileged groups
Delegated administration
Unauthorized privilege assignments

Attack Path Analysis

Review:

Privilege escalation paths
Tier violations
Administrative exposure
Inherited permissions

Recommended Assessment Tools

BloodHound
SharpHound
PowerView
PingCastle

Phase 2: Credential Security Assessment

Objective

Evaluate risks associated with passwords, authentication mechanisms, and service accounts.

Areas to Review

Password Policy

Assess:

Minimum password length
Complexity requirements
Password history
Account lockout settings
Fine-grained password policies

Service Accounts

Review:

Legacy service accounts
Shared credentials
Unmanaged passwords
Privileged service accounts

Managed Service Accounts

Verify implementation of:

Managed Service Accounts (MSA)
Group Managed Service Accounts (gMSA)

Kerberos Security

Assess:

Kerberos encryption types
Use of AES
Legacy RC4 support
Kerberos delegation settings

Key Risks

Weak passwords
Password spraying exposure
Service account abuse
Kerberoasting exposure
AS-REP roasting exposure

Phase 3: Privilege Escalation Assessment

Objective

Identify opportunities that enable attackers to elevate privileges.

Permission Review

Assess:

GenericAll
GenericWrite
WriteOwner
WriteDACL
ForceChangePassword

Delegation Security

Review:

Unconstrained Delegation
Constrained Delegation
Resource-Based Constrained Delegation (RBCD)

Active Directory Certificate Services (AD CS)

Assess:

Certificate templates
Enrollment permissions
ESC vulnerabilities
Certificate abuse opportunities

Local Administrator Exposure

Review:

Shared local administrator passwords
Administrator reuse
Lack of LAPS implementation

Common Findings

Excessive ACL permissions
Privileged account sprawl
Dangerous delegation configurations
AD CS misconfigurations

Phase 4: Lateral Movement Assessment

Objective

Evaluate how an attacker could move across the environment after obtaining initial access.

Assessment Areas

Administrative Access Exposure

Review:

Workstation administration
Server administration
Privileged workstation usage

Remote Management Protocols

Assess:

RDP
WinRM
WMI
SMB

Credential Exposure

Review systems storing:

Cached credentials
Administrative sessions
Service account credentials

Tiering Violations

Identify:

Domain Admin sessions on workstations
Administrative account misuse
Cross-tier authentication

Key Risks

Credential theft
Hash reuse
Ticket reuse
Privileged session exposure

Phase 5: Persistence & Trust Assessment

Objective

Identify weaknesses that could allow long-term unauthorized access.

Assessment Areas

Trust Relationships

Review:

Domain trusts
Forest trusts
External trusts
Selective authentication

Administrative Backdoors

Assess:

Privileged groups
Delegated permissions
Legacy administrative accounts

Security Configuration Review

Review:

SID History
AdminSDHolder
KRBTGT protection
Tier Zero exposure

Forest-Wide Risks

Trust abuse
Privilege inheritance
Cross-domain compromise
Transitive trust exposure

Active Directory Hardening Review

Identity Protection

Recommended Controls

Implement Tier-0 Administration
Deploy Privileged Access Workstations (PAWs)
Enforce Multi-Factor Authentication (MFA)
Implement Protected Users
Deploy Microsoft LAPS
Implement gMSA

Kerberos Hardening

Recommended Controls

Enforce AES encryption
Rotate KRBTGT regularly
Disable legacy protocols
Restrict delegation
Review service account configurations

Active Directory Certificate Services Security

Recommended Controls

Audit certificate templates
Restrict enrollment permissions
Remove vulnerable templates
Monitor certificate enrollment activities
Conduct regular AD CS reviews

Privilege Management

Recommended Controls

Review Domain Admin memberships
Eliminate unnecessary privileges
Restrict delegation
Remove dormant privileged accounts
Apply least-privilege principles

Attack Surface Reduction

Recommended Controls

Remove unconstrained delegation
Audit Active Directory ACLs
Reduce privileged group memberships
Remove stale accounts
Secure service accounts

Monitoring & Detection

Recommended Controls

Enable advanced auditing
Monitor privileged account activity
Monitor Kerberos anomalies
Monitor DCSync activity
Deploy honeytoken accounts
Integrate with SIEM platforms

Recommended Platforms

Microsoft Sentinel
Splunk
Wazuh
QRadar

Assessment Deliverables

Executive Summary

Provide:

Overall security posture
Critical risks
Business impact
Strategic recommendations

Attack Path Analysis

Provide:

Privilege escalation paths
Exposure diagrams
Trust relationship risks
Tiering violations

Detailed Findings

Each finding should include:

Risk rating
Description
Evidence
Impact
Remediation
Validation steps

Conclusion

An Active Directory Security Assessment provides organizations with visibility into identity-related risks, privilege escalation paths, trust relationships, credential exposure, and security control effectiveness. By combining thorough assessment activities with strong hardening measures such as Tier-0 administration, MFA, LAPS, gMSA, Kerberos hardening, AD CS review, and continuous monitoring, organizations can significantly reduce the likelihood and impact of Active Directory compromise while strengthening their overall security posture.