Understanding and Defending Against Active Directory Threats

Developed by Microsoft for Windows domain networks, Active Directory (AD) encompasses a broad range of directory-based identity-related services. Through this, IT administrators manage users, applications, data, and various other critical aspects of an organization’s network. If the Active Directory security gets compromised, it would risk user credentials, company systems, sensitive data, software applications, and more from multiple connected systems.

Common threats

A security compromise of AD, particularly that which is not detected early enough, can undermine the integrity of identity management infrastructure and may lead to widespread data leakage or system corruption. At any given time, various devices used within an organization may be vulnerable to external attacks due to various reasons such as:

• Having a default security setting;
• Using weak passwords for service accounts;
• Giving privileged access to employees than required;
• Lack of timely patching of vulnerabilities on AD Servers;
• Unreported unauthorized access, and more.

Six Best Practices

Below are some best practices to ensure holistic security around Active Directory.

1. Approve few admins and review permissions in AD roles: While employees need to have the minimal level of access they need to perform their roles, only some people should have the ability to make domain-level changes. Apply strong privileged access management (PAM) policies and security controls.
2. Separate Admin and User role: For day to day activities and AD administration, sysadmins should prefer using a different account. Also, other hosts should be dealt with outside the admin workspace, or be kept at an arm’s length from workstation. This prevents the admin credentials from getting exposed.
3. Use a Secure Admin Workstation (SAW): A SAW is a dedicated system only used to perform administrative tasks with only privilege accounts ensuring theft prevention and systems free of malware. AD admins can use both virtual or physical SAW that are locked down or free from infection. Also, it should be prohibited from browsing the internet, and, if possible, should not have any internet access.
4. Real-time Windows auditing and alerting: Conduct reporting of all the unauthorized access attempts. Provide full window auditing for access from within or outside the organization. Further, ensure that audit policy settings are configured in group policy and applied to all the computers and servers. There are ready-made tools available to barge in your AD and steal or spoof admin credentials (there are some on GitHub too). Make sure you’re versed with those and implement the right measures to detect and protect your system.
5. Ensure updated AD backup and recovery: Keep the AD backup configuration updated and practice the disaster recovery process for faster recovery. In case AD is breached, make sure you can restart domain controllers from the last secure version. For systems at remote locations where physical safeguards aren’t provided, at least verify that the hardware isn’t at risk.
6. Identify and patch all vulnerabilities on time: Any delays in patching a known vulnerability can lead to long lasting consequences for an organization. Ensure a fast and automated patching and maintenance process for AD and other critical systems. Either remove or update out-of-date software which are no longer supported.

Besides the aforementioned practices, do all that you find can safeguard your AD. Developing comprehensive visibility, management, auditing, and reporting capabilities can enhance your AD security and ensure systems integrity in the long run.