Active Directory (AD) is a cornerstone of the modern enterprise IT infrastructure. It's a directory service developed by Microsoft for Windows domain networks, serving as an essential tool for organising and managing users, their attributes and group membership, computer accounts, network resources and much more.

AD is like a phone book for your IT infrastructure and users. It equips teams with centralised authentication and authorisation services intended for Windows-based computers. AD is designed to check if someone has the right credentials (authentication) and determines what files or applications they can access based on their role or group membership (authorisation).

In simple terms AD offers key features and components like group policy management, domain services and lightweight directory access protocol (LDAP) support.

  • Group policy management allows administrators to implement specific configurations across multiple machines.
  • Domain services provide a hierarchical organisational structure that helps manage interactions between users and devices in distributed networks.
  • LDAP or Lightweight directory access protocol (LDAP) is a protocol that helps users find data about organisations, persons and more.

AD plays a crucial role in maintaining orderliness while ensuring security across an organisation’s complete enterprise network environment. It enables teams to effectively manage users, computers, additional devices and other resources from one central location, making network, IT and security management more efficient.

Cybersecurity Education and Training Begins Here

Start a Free Trial

Here’s how your free trial works:

  • Meet with our cybersecurity experts to assess your environment and identify your threat risk exposure
  • Within 24 hours and minimal configuration, we’ll deploy our solutions for 30 days
  • Experience our technology in action!
  • Receive report outlining your security vulnerabilities to help you take immediate action against cybersecurity attacks

Fill out this form to request a meeting with our cybersecurity experts.

Thank you for your submission.

What Is the Purpose of Active Directory?

Active Directory stores information as “objects”, which are any resources within the network, such as computers, user accounts, contacts, groups, organisational units and shared folders. Objects are categorised by name and attributes. The information is kept in a structured data store optimised to enhance query performance and scalability, which makes it easy for network users and applications to locate and use any needed bits of information. So, the purpose of Active Directory is to enable organisations to keep their network secure and organised efficiently.

What Is Active Directory Domain Services?

As the primary directory service in a Windows domain, Active Directory Domain Services (AD DS) is responsible for storing and managing information about users, services and devices connected to the network in a tiered structure. It’s basically the backbone of Active Directory as it contains a centralised directory that lets domains and users communicate.

AD DS helps manage network operations by providing a structured way to store data in a hierarchical organisation. This makes it easier for administrators to manage user access rights and system configurations across different domains within the same network. AD DS also integrates security by authenticating login functions and controlling access to directory resources. It does this through:

  • User authentication. AD DS authenticates users before they can access resources on the network, ensuring only authorised individuals have entry to specific parts of the system.
  • Data storage. It stores directory data, like usernames, passwords and phone numbers, which help streamline operations within an organisation.
  • Policies enforcement. With group policy objects (GPO), administrators can enforce security policies across multiple machines at once, saving time while maintaining high levels of security.

Multiple services fall under the umbrella of AD DS. These services include domain controllers, which are servers running the AD DS role that authenticate and authorise all users. They also include computers in a Windows domain-type network, which assign and enforce security policies for all devices, including software installation and updating.

Components of Active Directory Infrastructure

Active Directory infrastructure is comprised of several components that work together seamlessly for efficient networking operations:

  • Domains. A logical group where all objects—such as computers and users—reside under specific administrative control.
  • Forests. A collection of multiple trees that share a common schema but do not form a contiguous namespace.
  • Trees. A hierarchical arrangement containing one or more domains connected via trust relationships.
  • Organisational units (OUs). A container object within a domain containing other objects like users, groups and computers.
  • Group policies. A collection of settings that define how computers and users operate within an organisation.

Domains group together network objects and apply security policies. Forests contain domain trees and share a single schema and data configuration. Trees are collections of related domains that simplify resource location. And OUs are containers within a domain that simplify management tasks. Together, these components work harmoniously to optimise the efficiency and performance of an Active Directory.

Benefits of Using Active Directory

Active Directory provides more than just a unified directory service. It is also an invaluable asset for organisations aiming to simplify their IT operations and strengthen their security. In turn, AD offers several key benefits.

Streamlined User Management

AD simplifies user account management by providing a centralised platform to create, modify or delete users across the entire network. This means that manual administration of users on individual machines within your network is a thing of the past.

Enhanced Network Security

AD’s robust security features safeguard sensitive data against cyber threats. Group policies and access controls enforce strict password requirements and limit users’ access to specific files or applications based on their specific roles within the company.

Simplified Resource Sharing

Sharing resources like printers or files across a network is much simpler with AD. Administrators can manage these resources centrally, making them available to all users without additional software installation.

Better Group Policy Implementation

The Group Policy feature in AD enables admins to control how systems operate and what users can do on those systems. From setting up firewall rules to disabling USB ports on endpoints for enhanced security--everything becomes easier with group policies in place.

Faster Troubleshooting

When issues arise, having a centralised system like AD helps diagnose problems faster by providing detailed logs about user activities and system events.

Active Directory Security

Active Directory offers security features like access control lists (ACLs), encryption and auditing capabilities to protect sensitive data and resources. These are all important features to employ. But comprehensive and ongoing Active Directory security involves many other steps and strategies.

The following are some best practices for Active Directory security:

Strongly Secure Domain Administrator Accounts

Attackers are eager to compromise domain administrator accounts associated with your AD. That’s because these Active Directory users have high privileges with administrative control and authority over an entire domain within an AD “forest”. (A forest is a collection of one or more domain trees in the service directory.)

One tip to secure domain admin accounts is to rename them from the default “administrator” to something more creative (and harder to guess). Implementing strong password policies and using passphrases can help here. Another good practice is to require MFA for authentication for domain administrators

Limit the Use of Highly Privileged Access to AD

Authorised personnel are the only users who should have administrative access in your AD. And those who have domain administrator privileges should not use those accounts for everyday tasks. For those they should use more typical user level accounts. Related measures for limiting Active Directory access—which can also help to reduce the risk of insider threats—include:

  • Implementing the principle of least privilege (PoLP) to grant users only the permissions they need to perform their work—and no more.
  • Using role-based access control (RBAC) to limit user access to specific tasks or systems.
  • Auditing administrative accounts regularly.


Use a Locked-Down Secure Admin Workstation (SAW)

A SAW is a highly secure and isolated environment for performing administrative tasks in critical systems and services like Active Directory. The admin must originate from the SAW before they can perform any administrative task or connect to any other administered server or network. Some of the ways to “lock down” a SAW include:

  • Using dedicated hardware or a virtual machine (VM) for administrative tasks.
  • Hardening the SAW’s operating systems—for example, by disabling unnecessary services and features.
  • Implementing strict access controls and user privilege management.
  • Placing the SAW in a separate network segment.
  • Reducing or eliminating direct internet connectivity to the SAW.


Disable Local Administrator Accounts

Local admins also have high privileges. But unlike domain admins, they are restricted to one, local machine. Local administrators have complete access to resources on the local server or client, though. And they can use their account to create local users, to assign user rights and access control permissions and to install software.

Local admin accounts are often configured with the same password on every computer in a domain. So, an attacker only needs to compromise the credentials for one account to sign into others. Not surprisingly, bad actors often use unmanaged local administrator credentials in ransomware attacks.

You may want to consider disabling local admin accounts completely. You can instead set up individual accounts with the necessary rights to complete key tasks. To disable a local admin account, you will need to modify Group Policy settings in the Active Directory. Then, you can enforce security policies on Windows computers that are joined to the domain.

Use Managed Service Accounts (MSA)

MSA accounts have complex passwords that AD manages automatically. The AD domain controller rotates the passwords regularly, so the risk of passwords for service accounts being weak, stale or exposed is reduced. By eliminating manual password changes the likelihood of human error is minimised. So, too, is the risk of service disruptions due to password changes.

(Note: MSAs are available in Windows Server 2008 R2 and later, including Windows Server 2012, 2012 R2, 2016, 2019 and 2022. The specific features and capabilities of MSAs may vary depending on the version of Windows Server in use.)

Find and Remove Unused Accounts

Creating a formal process to identify inactive users and unused or orphaned accounts in your AD can help ensure you stay on top of this risk. As part of that process, you will need to determine the criteria for identifying inactive accounts, such as a specific period of inactivity (like 90 days). You should also notify relevant stakeholders to make sure that the identified accounts can be deleted safely.

Taking the time to back up your AD environment before you start to remove accounts is also a wise practice. You may want to document the accounts you plan to remove and cite the reasons for deleting them, just so you have a record.

Be Vigilant About Patch Management and Vulnerability Scanning

This tip may seem mundane or obvious. However, you need to move fast to patch Active Directory vulnerabilities, just as you should do to protect any other critical system. Be sure to scan for and remediate AD vulnerabilities often—once a month or on a more frequent basis, if possible. Prioritise fixes that pose the most serious risk to your business and users. And identify and address any outdated or unsupported software as well.

By implementing these security best practices, organisations can strengthen their AD security posture and minimise the risks to their IT infrastructure.

Active Directory: The Authority in Enterprise Resource Management

Active Directory is the ultimate directory service that keeps stored data organised, optimised and secure. With Active Directory Domain Services (AD DS), IT teams can create a hierarchy of domains and subdomains, which makes managing user authentication, authorisation and resource management easier.

In turn, the value of using AD includes increased security, simplified administration and better scalability. But teams must implement best practices like strong password policies and regular monitoring to keep their AD environment secure.

Ready to Give Proofpoint a Try?

Start with a free Proofpoint trial.