What is Active Directory Security? AD Security Explained

Want to know how to secure Active Directory? Check out the latest Active Directory tools, practices, and hardening checklist items. Prevent major Active Directory threats and ward off AD attacks.

Active Directory in cybersecurity makes up  a collection of security measures and practices. Active Directory (AD) was first introduced by Microsoft as a means to manage and organize info about computers, users, and resources on a network. AD security plays a big role in centralizing authorization, authentication, and the overall security management of Windows-based environments.

Why Active Directory Security Still Matters in 2025

2026 is coming soon, so the importance of Active Directory Security cannot be understated. Centralized access in 2025 also means centralized risks, Without Active Directory protection, you risk compromising user accounts and letting lateral movement attacks spread.

Insider threats are so very real. One employee or contractor can make your business come crashing down. Credential theft is a top attack vector. Stolen and weak passwords are one of the easiest ways to breach into your AD environments.

Attackers also exploit your AD by using ransomware as a launchpad. They can cripple entire networks in hours and not care. There are also other reasons why you want strong AD security such as:

• To prevent shadow IT attacks
• For detecting threats and anomalies in real-time
• Meeting compliance demands and ensuring business continuity
• Reducing IT overheads and for future-proofing your enterprise by building a zero trust network security architecture

What Are the Major Threats & Attack Techniques Against Active Directory?

These are the major threats and attack techniques used against Active Directory:

Account-Based Attacks

Account-based Active Directory (AD) attacks will go after your users and try to compromise their credentials. Here is how the major ones work:

Golden Ticket (T1558.001)

Golden Ticket Attacks  are a sub-technique of the Steal or Forge Kerberos Tickets: Golden Ticket (T1558.001). They can compromise entire networks and grant unauthorized access to domain resources.

It operates with tools like Impacket and Mimikatz to evade detection, and manipulates the Kerberos authentication protocol within Windows networks.

Silver Ticket

Silver Ticket attacks will work in a different way. They compromise your user credentials and abuse the design of the Kerberos protocol. Silver Ticket attacks will let the attacker forge ticket-granting (TGS) tickets for targeted services. They come encrypted with a password hash and these TGS tickets can be minted for those services. Silver Ticket attacks basically offer stealthy and persistent access to resources, requiring only the service account's password hash to access them.

Over-privileged service accounts

Non-human accounts that have excessive permissions and controls are dubbed as over-privileged accounts in the Active Directory. They can cause data breaches, credentials theft, and operational disruptions.  Whatever permissions they hold, they're more than what's necessary in networks.

Credential Theft

Active Directory (AD) credential theft attacks will steal usernames, passwords, and other authentication data. Here is how they work:

Pass-the-Hash (T1550.002)

Pass-the-Hash (PtH) (MITRE T1550.002) is a lateral movement attack where the adversary will steal your password hash via a compromised system. They will use this to authenticate themselves on another system as a legit user.

Pass-the-Ticket (T1550.003)

Pass-the-Ticket (PtT) (MITRE T1550.003) will reuse stolen Kerberos tickets. to get unauthorized access to resources on your networks. Attackers will use Mimikatz to extract TGTs from your system's memory. They'll inject these stolen tickets into their own sessions and impersonate legit users to gain access to exclusive services.

Kerberoasting (T1558.003)

Kerberoasting (MITRE T1558.003) is a harvesting and service account cracking technique for accounts that are offline. Any authenticated domain user can do this. There is no risk of getting detected on the network and threat actors can avoid account lockout policies since it's an offline attack. As long as SPNs are linked to user accounts, you will be vulnerable.

AS-REP Roasting

This is a credential dumping attack that exploits misconfigurations in your Active Directory. The attacker will first find accounts with the 'Do not require Kerberos preauthentication' setting enabled. He/she will send an Authentication request (AS-REQ) to a domain controller on behalf of a user who is vulnerable. No password needs to be given since pre-authentication is enabled, and that's how the attacker gets a valid Authentication Server Response (AS-REP) that contains the Ticket-Granting Ticket (TGT) in return.

Directory Service Exploitation

Here are some ways attackers can exploit Active Directory services:

DCsync/DCShadow (T1003.006/T1528)

DCSync attack dumps credentials which exploit AD's replication process. The attacker can impersonate domain controls and request another to replicate sensitive password data, directly for them.

DCShadow attacks will push malicious changes thanks to higher level privileges obtained by the attacker. It's a great stealth persistence technique and can force compromised machines to pose as rogue Domain Controllers on networks.

Exploiting AD Certificate Services (ESC1–ESC8 attack paths)

ESC1 attack paths involve using vulnerable certificate templates to exploit misconfigurations. The attacker can use tools like Certipy to identify these templates and request certificates on behalf of users. They can authenticate themselves as privileged users and launch more attacks by using those certificates.

ESC8 (NTLM Relay) will take advantage of misconfigured AD CS web enrollment services. They use NTLM authentication instead of HTTP and can force privileged accounts to authenticate malicious services by relaying NTLM hashes.

Abuse of trusts and delegation

Attackers can abuse trusts in multi-domain environments which let users get access to other resources. They can escalate privileges in trusted domains and compromise machines with unconstrained delegations.  Resource-based constrained delegation (RBCD) is another way they get in and misconfigure services running on systems to escalate their privileges.

Replication Attacks

Active Directory replication services can push malicious changes and try to steal credentials by exploiting the directory. Here is how replication attacks work:

• Unauthorized replication requests (DCsync): It lets an attacker impersonate a Domain Controller (DC) and request sensitive data.
• Shadow Domain Controller (DCShadow): It's a high stealth technique where the attacker will register a rogue DC. The rogue will push malicious changes into the directory via normal replication.
• Persistence via AdminSDHolder/ACL abuse: The attacker will gain persistent access via a compromised privileged account. He/she modifies permissions on the AdminSDHolder object. It will automatically revert manual changes on permissions for protected groups as well.

How to Harden Active Directory: Best Practices & Checklist

Here is your Active Directory security hardening checklist. It also lists Active Directory security best practices which you can follow:

• Administrative accounts should restrict access via privileged access management. Remove unnecessary permissions and apply the model of least privilege access rights. Prevent credential sprawl across your domain environment by regularly auditing accounts.
• Jump servers can provide controlled access points and prevent lateral movement during potential breaches. Create network segmentation between regular users and domain management tasks. Make sure you secure your admin workstations and do tiering.
• Do LDAP signing because it prevents man-in-the-middle attacks while channel binding stops credential relay attempts against your directory services.
• Set strong password policies and automated password rotation for service accounts to reduce attack surfaces. Change passwords often and make sure they’re unique to make credential-based attacks more difficult for threat actors to execute.
• Certificate Services will need proper templates and enrollment controls to harden them. You’ll need to carefully configure Federation trusts to prevent cross-domain privilege escalation and unauthorized resource access attempts.
• Check your workstations, apps, member servers, and data repos to make sure you haven't granted any excessive privileges to user accounts. Start using secure admin hosts and check your physical security for them as well, besides system and network security.
• You can set security configuration baselines for your domain controllers and enforce with group policy objects (GPOs).  Use advanced audit policies and classify your AD data.

How to Detect Active Directory Attacks: Monitoring & Threat Detection Signals

There are lots of signals to watch in Active Directory environments that can help you monitor and stop attacks in their tracks. Here is what to look for:

Logs & Telemetry

Collect event logs from domain controllers. Check for Kerberos ticket requests and DC Diagnostics reports to spot unusual patterns. Keep an eye on spikes in ticket‐granting-ticket requests or repeated failed authentications from a single host. Correlate telemetry across services to pinpoint reconnaissance or privilege abuse.

Tools/Analytics

Use attack-path mapping tools and anomaly detection engines to visualize how credentials flow through your network. Network monitoring platforms track East-West traffic and identify odd SMB or RPC calls; they can reveal hidden lateral movement.

Indicators of compromise

Look for SPNs that appear on unexpected hosts, Kerberos tickets reused across multiple accounts, and sudden group changes. You should flag any account whose access rights change without an approved workflow or any ticket issued outside normal business hours.

How to Respond & Recover After an Active Directory Breach

Active Directory threats can wreak havoc on your organization when left unchecked. Here’s how to respond and recover after an Active Directory security breach:

You should immediately isolate any compromised accounts to prevent further damage. Revoke your tickets and reset password limits during forensic analysis. You should preserve any evidence you find for further investigation and recovery planning.

You need to restore your systems as well. Make clean backups and focus on NTDS database recovery. Forensic analysis can help you identify Active Directory attack techniques, vectors and compromised systems before bringing services back online safely.

Post-incident hardening should apply lessons learned from the breach. Change your configurations and do additional monitoring to prevent similar attacks while improving your organization’s overall security posture and detection capabilities.

What Tools & Technologies Enhance Active Directory Security?

Here are some tools and technologies that can enhance your Active Directory Security:

SIEM/EDR/Identity Threat Detection technologies

Security Information and Event Management systems collect authentication logs from domain controllers and scan behavioral patterns for indications of suspicious activity like credential theft or elevation of privilege. Endpoint Detection and Response systems proactively scan workstations for infections from malware as well as lateral movement attempts while Identity Threat Detection systems scan authentication anomalies in your hybrid environment. These systems cross-correlate events from multiple sources for indications of advanced persistent threats.

Cyber attack pathway management software + Identity/privilege management

Privileged Access Management software secures admin credentials in encrypted vaults and provides just-in-time access with automated approval workflows. These platforms model potential attack surfaces across your environment while requiring least privilege principles with automated password rotation of service accounts. Products like SentinelOne Singularity™ Identity Detection & Response also provide credential sprawl prevention via privileged account management with real-time session activity monitoring.

Monitoring, Automation and  Threat Hunting

Change monitoring controls monitor Active Directory object, group membership, and permission changes with real-time alerting. Automated systems recognize configuration drift, identify inactive accounts, and highlight anomalous authentication patterns that may be indicative of compromise. Threat hunting technologies integrate identity signals with network and endpoint data to identify advanced threats that escape conventional security controls.

Common Mistakes and Misconfigurations Put Active Directory at Risk

Frequent errors and misconfigurations jeopardize Active Directory's security. Open LDAP, weak passwords, over membership of privileged groups, misconfigured trusts, dormant accounts etc.

Many organizations leave LDAP channels unsigned. They create opportunities for credential interception and relay attacks during authentication processes. Weak password policies combined with excessive membership in Domain Admins groups expand attack surfaces unnecessarily. Misconfigured trust relationships between domains enable privilege escalation while dormant accounts provide persistent backdoors that evade normal monitoring systems. Without regular review cycles, service accounts can often get excessive permissions.

Emerging Trends & Risks in Active Directory Security

Here’s what to watch out for:

Hybrid AD + Azure AD integration risks

Hybrid cloud deployments by organizations create new attack surfaces as threat actors exploit sync gaps between on-premises and cloud identity infrastructures. Insufficiently configured deployments of Azure AD Connect and also of ADFS federation trusts create privilege escalation opportunities across both infrastructures. Identity sync services are seen by attackers as a means of attacking both on-premises and cloud credentials at the same time.

Cloud identity threats, supply chain threats, AI-adversary tactics

Advanced cyber threats use machine learning algorithms to scan lists of stolen credentials, thus automating sophisticated attack methods like password spraying and credential stuffing. Supply chain compromises increasingly target identity administrators and certificate authorities, while threat forces attack overprivileged cloud service principals and application identities that have too many privileges.

Policy/governance shifts and regulatory pressures

Compliance standards today mandate zero standing privileges as well as continuous identity monitoring with complete audit trails of each privileged activity. Companies must implement just-in-time access models with separation of duties and automated access reviews. New legislation drives adoption of identity governance technologies that mandate risk-based authentication as well as continuous verification of compliance.

Active Directory Security Metrics and KPIs You Should Track

Here are the key Active Directory security metrics and KPIs to track:

• Mean Time to Detect: You need to measure the speed at which your security team discovers potential threats from initial compromise to detection at an optimal response of detection within 30 minutes to 4 hours.
• Mean Time to Respond: This measures the time from threat detection until full containment and remediation. Both help measure the maturity of your incident response processes and your detection coverage of domain controllers and authentication systems.
• Exposure of privileged accounts: Keep tabs on the aggregate of accounts that hold privileged admin rights within your domain by monitoring membership changes of high-risk groups such as Domain Admins and Enterprise Admins.  You will need to track unused privileged accounts that have not been accessed within a certain timeframe, unsuccessful login attempts against admin accounts, as well as privileged session durations, plus off-hours privileged account usage indications.
• Legacy Protocol Usage: Monitor authentication attempts using outdated protocols like NTLM, unsigned LDAP, and older TLS versions that enable credential relay attacks..
• Audit Coverage: Track the number of domain controllers with complete logging enabled for authentication events, privilege changes, and policy modifications. You will need to identify gaps in log collection and retention across your AD infrastructure to prevent blind spots.
• Number of Stale Accounts: Check user and computer accounts that haven't been authenticated within defined timeframes, typically 90 days for users and 30 days for computers. Monitor cleanup activities and the ratio of active versus inactive accounts across your domain environment.

Active Directory Security with SentinelOne

If you want to know how to secure Active Directory, then here’s a solution:

Singularity™ Identity Detection & Response can help you end credential misuse via real-time infrastructure defense for Active Directory and defense for Active Directory and Entra ID. It defends domain controllers and domain-joined assets from adversaries aiming to gain privilege and move covertly.

You can detect AD attacks across the enterprise emerging from all managed or unmanaged systems on any OS, from any device type—including IoT & OT. You can steer attackers away from AD crown jewels, and instead misdirect them down dead-end alleys with lures and fake information. It can hide and deny access to local and cloud-stored data while simultaneously making lateral movement exceedingly difficult for attackers.

You can:

• Improve Active Directory security and gain visibility and awareness of attacker activity targeting critical domain servers
• Gain visibility into service account compromises that allow attackers to elevate privileges on endpoints.
• Identify Access Control Lists and delegation misconfigurations that give accounts elevated rights without proper membership.
• Protect high-value user, service, and system accounts from attacker compromise.
• Achieve fast time-to-value and get full coverage for on-premises Active Directory, Entra ID, and multi-cloud environments

Singularity™ Identity Detection & Response supports your Zero Trust Program and can limit implicit trust to applications and data resources with controlled access management functions. It will identify identity exposures on endpoints, AD, and the cloud to reduce your overall attack surface. It can detect identity attacks from either endpoints or domain controllers and alert on violations of identity trust.

You will understand the path to a breach and visually experience topographical maps that show how adversaries might advance their attacks from one system to another. By using it, you can discover hidden elements throughout the network that enable lateral movement, including exposed surfaces, orphaned credential assets, and policy violations. You can use our AI-SIEM  for log analysis and SentinelOne also has Singularity™ Endpoint for endpoint security.

Conclusion

Active Directory Security isn't a one-size-fits-all approach. It's a combination of measures, tools, and technologies, plus practices that you'll use to harden Active Directory environments. Take it one step at a time and start with the basics. Check your existing security infrastructure, user accounts, and do an audit. Then work your way up from there.

If you are looking for the best Active Directory security tools, then you can reach out to the SentinelOne team. Our services can help you out.

FAQs

What is AD Security?

Active Directory Security is a set of measures and controls that secure the Active Directory service infrastructure used for network authentication and access. The protection features incorporate solutions to secure domain controllers, secure authentication protocols, and control access to resources in the enterprise environment.

Why is AD Security essential?

Active Directory security acts as the foundation of enterprise network protection, managing resource access and authenticating users with true identity. Successful compromise of Active Directory possibly means a full network compromise, data theft, and only a matter of time until all services/systems become disrupted, affecting business continuity.

How do we detect and mitigate AD security breaches?

Breaches are detected by continuous monitoring of authentication events, directories, and account activities. To mitigate the breach, steps should be followed, such as isolating systems from the network that have been compromised, revoking access to accounts, resetting credentials, etc.

How do you respond to an Active Directory compromise?

If Active Directory was compromised, then any particular system and domain controller would need to be isolated immediately. Remediate KRBTGT accounts, check directory backups, confirm all privileged account credentials in organizations, and closely monitor remaining systems.

What are common Active Directory misconfigurations?

Some misconfigurations include overly permissive privilege access rights, weak passwords on service accounts, unnecessary trust relations between domains, or disabled security measures. Security gaps tend to be the result of the default configurations, which are something that attackers are able to exploit.

What is the Active Directory Security Checklist?

Security checklist includes security assessments, access control securities, Group Policy securities, domain controller securities, and many more. It is the responsibility of organizations to reinforce authentication protocols, track changes to directory services, and keep security patches up to date.

How can ransomware attacks on Active Directory be prevented?

Measures to prevent ransomware attacks include the implementation of secure authentication protocols, limiting administrative access, keeping up-to-date backups, and monitoring your networks for suspicious happenings. It is necessary for organizations to secure domain controllers and enforce network segmentation to reduce the attack spread.