Active Directory (AD) is a Microsoft Windows directory service that allows IT administrators to manage users, applications, data, and various other aspects of their organization’s network. Active Directory security is vital to protect user credentials, company systems, sensitive data, software applications, and more from unauthorized access. A security compromise of AD can essentially undermine the integrity of your identity management infrastructure, leading to potentially catastrophic levels of data leakage and/or system corruption/destruction.
Why It Is Critical to Secure the Active Directory System
Since AD is central to authorizing users, access, and applications throughout an organization, it is a prime target for attackers. If a cyber attacker is able to access the AD system, they can potentially access all connected user accounts, databases, applications, and all types of information, possibly jeopardizing security for an entire AD forest. Therefore, an Active Security compromise, particularly those that are not caught early, can lead to widespread fallout from which it may be difficult to recover.
Threats to Active Directory Systems
Let’s delve into several key areas where Active Directory systems may be susceptible to threats:
Default Security Settings: AD has a set of predetermined, default security settings created by Microsoft. These security settings may not be ideal for your organization's needs. Additionally, these default security settings are well-understood by hackers, who will attempt to exploit gaps and vulnerabilities.
Inappropriate Administrative Users and Privileged Access: Domain user accounts and other administrative users may have full, privileged access to AD. Most employees, even those in IT, do not need high-level or superuser privileges.
Inappropriate or Broad Access for Roles and Employees: AD allows administrators to grant access to specific applications and data based on employee roles. Roles are assigned to groups that determine access levels. It’s important to only allow the levels of access individuals and roles need to perform their job functions.
Uncomplex Passwords for Administrative Accounts: Brute force attacks on AD services often target passwords. Uncomplicated passwords and easily guessable passwords are most at risk.
Unpatched Vulnerabilities on AD Servers: Hackers can quickly exploit unpatched applications, OS, and firmware on AD servers, giving them a critical first-foothold within your environment.
Lack of Visibility and Reporting of Unauthorized Access Attempts: If IT administrators have awareness about unauthorized access attempts, they can more effectively disrupt or prevent such access attempts in the future. Thus, a clear Windows audit trail is vital to identify both legitimate and malicious access attempts, and to detect any AD changes that have been made.
Best Practices for Active Directory Security
There are at least 7 best practices IT departments should implement to ensure holistic security around Active Directory:
1. Review and Amend Default Security Settings
After installing AD, it's vital to review the security configuration and update it in line with business needs.
2. Implement Principles of Least Privilege in AD Roles and Groups
Review all the necessary permissions for data and applications for all employee roles in the organization. Ensure that employees have only the minimal level of access they need to perform their roles. Also ensure separation of privileges, so there is tighter auditability between roles and to help prevent lateral movement in the event an account is compromised. Apply strong privileged access management (PAM) policies and security controls.
3. Control AD Administration Privileges and Limit Domain User Accounts
Carefully review all IT staff and only provide administrative privileges and superuser access to those who absolutely need this access to perform their roles. Use PowerShell Just Enough Administration (JEA) and/or a PAM solution to ensure this access is limited in the most granular way practical. Ensure these accounts are properly protected with robust passwords.
4. Use Real-Time Windows Auditing and Alerting
Conduct reporting of unusual access attempts. Provide full windows auditing and alerting of any access from inside or outside the organization. Pay special attention to Windows AD change auditing. This will also help to meet PCI, SOX, HIPAA, and other compliance requirements.
5. Ensure Active Directory Backup and Recovery
Backup the AD configuration and directory on a regular basis. Practice disaster recovery processes to allow for fast recovery in case AD integrity is breached.
6. Patch All Vulnerabilities Regularly
Identifying and patching vulnerabilities is one of the IT department’s most important tasks. Ensure a fast, efficient, and effective patching and maintenance process for AD and other flaws.
7. Centralize and Automate
Centralize all reviews, reports, controls, and administration in one place, and look for tools that can provide automated workflows for alerting and helping to reconcile issues.
Understanding AD vulnerabilities and implementing security and least privilege access controls is vital to protecting domain accounts and keeping the IT ecosystem safe. Proper visibility, management, reporting, and auditing capabilities can significantly enhance AD security and ensure systems integrity.
Matt Miller, Senior Content Marketing Manager, BeyondTrust
Matt Miller is a Senior Content Marketing Manager at BeyondTrust. Prior to BeyondTrust, he developed and executed marketing strategies on cyber security and cloud technologies in roles at Accelerite (a business unit of Persistent Systems), WatchGuard Technologies, and Microsoft. Earlier in his career Matt held various roles in IR, marketing, and corporate communications in the biotech / biopharmaceutical industry. His experience and interests traverse cyber security, cloud / virtualization, IoT, economics, information governance, and risk management. He is also an avid homebrewer (working toward his Black Belt in beer) and writer.