Many organizations use Active Directory (AD) to manage users, devices, and networks in a Windows computing environment. This reliance on the platform makes it an attractive target for threat actors. AD is a company’s central identity control plane, and a successful incursion on the platform can have devastating consequences, including data exfiltration and ransomware attacks.
Unfortunately, traditional security tools such as antivirus software and perimeter firewalls offer insufficient protection for Active Directory. We are going to examine the flaws in AD security and how threat actors can exploit them to put your business at risk. We will also explore how VAST can help provide additional AD protection with the Semperis security suite.
What are Active Directory Core Functions?
Businesses typically use AD for five core functions.
- Centralized authentication: AD verifies user and device identities during sign-in using NTLM and Kerberos. This centralization reduces password sprawl and enables single sign-on (SSO) across the organization.
- Authorization and access control: AD enforces permissions and determines what authenticated users can do with access control lists (ACLs), security groups, and role-based access controls (RBAC). Teams can enforce least-privilege access and enforce organizational security controls.
- Directory services: AD provides identity and object management by storing and organizing resources such as users, computers, groups, service accounts, and other infrastructure resources. Companies obtain a single, authoritative identity source in AD’s directory services, which facilitates scalable IT administration.
- Policy management: Companies can enforce a consistent security posture with AD by applying security and configuration settings through Group Policy objects (GPOs). Teams can use GPOs to control password policies, implement security baselines, and distribute login scripts.
- Trust relationships: AD establishes trust relationships between Windows components such as domains, forests, and external directories. These relationships are critical for enabling secure access across organizational boundaries and for integrating with cloud identity solutions such as Azure AD.
Common Active Directory Security Gaps
Potential gaps in AD security offer threat actors multiple opportunities to attack an organization’s IT environment. The way an organization uses AD often exposes these security shortcomings. Many AD weaknesses originate from logical and behavioral issues rather than direct malware attacks.
The following issues illustrate some of the dangers of ineffective management and oversight of the AD platform that traditional security tools miss.
Privilege creep
Over time, users and service accounts accumulate permissions and privileges that may remain active despite changing roles. Group membership can be nested and can hide domain-admin-level access to system resources. Traditional security tools focus on identifying malicious code and intruders, not on who has privileged access. Attackers can use compromised, over-privileged accounts to compromise the IT environment.
Active Directory misconfigurations
Teams may make configuration mistakes, such as defining weak ACLs or inadequate permissions on sensitive objects. These misconfigurations affect directory logic that legacy security solutions cannot detect. Threat actors can leverage faulty directory permissions to gain domain admin access to the Windows environment.
Inactive and orphaned accounts
Traditional security solutions do not address the risks of extended or unmonitored account lifecycles. Attackers can exploit active, default vendor or application accounts. They can leverage privileged test accounts that were not deleted and inactive users with privileged group membership.
Unsecured service accounts
AD can be compromised via service accounts with default, never-expiring passwords or that have domain admin permissions. These accounts are prime targets for threat actors, as they represent high-value attack paths that are difficult to monitor.
Reliance on logs
Teams may become over-reliant on logs to ensure security. But logs only show what has happened to the environment. They cannot show what could happen if, for example, account credentials are compromised. Many AD attacks appear to exhibit normal behavior, exploit trust relationships, and are difficult or impossible to identify with traditional logging solutions.
Ineffective security assessments
Active Directory is a dynamic environment where permissions and trust relationships are constantly changing. Traditional annual or monthly audit and assessment methods may allow the security posture to slowly and silently degrade. A motivated attacker can eventually find a weak link and compromise an account.
Common Active Directory Attacks
Threat actors exploit AD security gaps to launch attacks, gaining access to accounts and credentials to steal data, deliver ransomware, or cause other types of damage. The following AD attack techniques leverage the platform’s security gaps.
- Credential dumping: Attackers dump cached domain credentials or those in memory as admins log in to servers and workstations. Threat actors gain immediate access to privileged credentials and can rapidly move laterally throughout the environment.
- Password spraying: This type of attack abuses valid accounts and credentials to gain initial entry into an environment without detection by traditional security tools. Hackers spray common passwords across many accounts in the hope that at least one will work and allow them to access the environment.
- Group Policy Object hijacking: In this attack, the perpetrators modify existing GPOs or create new GPOs to support their goals. Attackers can deploy malicious startup scripts and scheduled tasks via GPOs and quickly spread ransomware across a domain.
- Access control list abuse: Threat actors exploit excessively permissive ACLs to modify user privileges and group memberships. These apparently legitimate changes allow attackers to evade detection and enable persistent threats with escalated privileges, posing long-term risks.
- Kerberoasting: Attackers request Kerberos service tickets for service accounts and attempt to crack them to recover plaintext passwords. They exploit compromised service accounts to gain Domain Admin access.
VAST’s Solution for Enhanced Active Directory Security
Semperis is a multifaceted software solution that provides outstanding protection for an AD environment. VAST’s partnership with Semperis lets us help your company leverage this advanced security solution to safeguard Active Directory. Semperis has four main components that work together to protect AD.
- Semperis Directory Services Protector (DSP) is the first line of defense. It continuously monitors the AD environment, rolls back malicious changes, identifies advanced exploits, and reduces the attack surface.
- Semperis Active Directory Forest Recovery (ADFR) provides fast, effective recovery for an attacked AD environment. The tool’s features include post-breach forensics to avoid follow-up attacks and recommendations to close security gaps.
- Purple Knight is a free, AD security assessment tool that helps businesses discover indicators of exposure (IoEs) and indicators of compromise (IoCs) in hybrid AD environments. VAST assists in running and interpreting the assessment results to address security gaps before they are exploited.
- Cohesity Identity Resilience works with Semperis to enhance your security posture and minimize successful AD attacks.
Contact our team of experts and learn more about how we can help you protect your AD environment from risks missed by traditional security solutions.
