Active Directory Security Overview

Active Directory (AD) is a critical component of enterprise IT infrastructure, managing users, computers, and permissions. Ensuring its security is vital to prevent unauthorized access, data breaches, and cyberattacks. Below is a structured overview of AD security risks, best practices, and hardening techniques.

Key Concepts: Active Directory is organized into forests (the top-level trust boundary) and domains, each containing objects (users, computers, groups, service accounts, etc.). Domain Controllers (DCs) host copies of the directory and authenticate sign-in requests. An Organizational Unit (OU) is a container for organizing objects, and Group Policy Objects (GPOs) apply security settings to users and computers. AD uses Kerberos (and legacy NTLM) for authentication, and every object has an Access Control List (ACL) defining its permissions. AD also defines built-in privileged accounts (like Domain Admins, Enterprise Admins, Administrators, and the special krbtgt account). Together, these components form the AD security perimeter. Properly securing AD means hardening each part (e.g. enforcing strong password policies, limiting privileged roles, and monitoring authentication) so that even if attackers breach one account, they cannot easily escalate privileges learn.microsoft.comsemperis.com.

Common Active Directory Attack Techniques

Attackers have developed specialized techniques to exploit AD’s protocols and misconfigurations. Some common post-compromise attacks include:

• Pass-the-Hash (PtH): Stealing an account’s NTLM hash (instead of its plaintext password) and using that hash to authenticate elsewhere. This abuses Windows’ NTLM authentication to move laterally without knowing the actual password. Tools like Mimikatz automate dumping NTLM hashes from memory. For example, once an attacker has local admin on a machine, they can extract the hash for a domain account and use it to log into other systems as that user netwrix.com. This technique has been used in numerous breaches; it lets attackers pretend to be any compromised account without ever “cracking” the password. (Microsoft’s LAPS tool can help mitigate PtH by ensuring local admin passwords are unique per machine learn.microsoft.com.)
• Kerberoasting: Exploiting Kerberos service tickets to extract service account credentials. In AD, service accounts running network services are associated with Service Principal Names (SPNs). An attacker can query AD for SPNs and then request Kerberos Ticket-Granting Service (TGS) tickets for those accounts. Crucially, each TGS ticket is encrypted with the service account’s password-derived key. The attacker can then attempt to brute-force or GPU-crack the ticket offline to recover the service account password microsoft.comtriaxiomsecurity.com. Because many service accounts have long-lived, weak passwords (as illustrated by an audit finding one MSSQLSvc account password unchanged since 2012 triaxiomsecurity.com), Kerberoasting often succeeds with minimal detection. The cracked password often turns out to be high-privilege (sometimes even Domain Admin), giving the attacker full domain control triaxiomsecurity.com. Defense: Require very strong, regularly rotated passwords for service accounts (or use Group Managed Service Accounts, gMSAs) and enable AES encryption for service tickets microsoft.commicrosoft.com. Detect by monitoring for unusually many service ticket requests or tickets encrypted with weak ciphers like RC4 microsoft.commicrosoft.com.
• Golden Ticket: Forging Kerberos Ticket-Granting Tickets (TGTs) by stealing the hash of the krbtgt account (the account that “signs” all TGTs). Once an attacker has the KRBTGT NTLM hash (e.g. via a DCSync attack below), they can use it to create golden tickets for any account in the domain semperis.com. This essentially grants the attacker perpetual Domain Admin privileges until the krbtgt password is reset twice. In effect, the attacker can then access all resources in the domain undetected. Golden Tickets have been observed in major breaches (e.g. the APT group referred to as APT15/Ke3chang is known to use them semperis.com). Defense: Store krbtgt hashes in an isolated manner, use a Tiered Admin model to limit who has those credentials, and after any suspected compromise reset the KRBTGT account password twice to invalidate old tickets semperis.comsemperis.com. Regularly audit for unusually long-lived or forged Kerberos tickets.
• Silver Ticket: Similar to a Golden Ticket but less powerful: the attacker forges a Kerberos service ticket for a specific service by using that service’s account key. This requires only that one SPN’s password hash, and it is used to access a single service (not the entire domain). (Citing: CrowdStrike explains Silver Ticket as forging a TGS for a single service when an attacker has its password hash crowdstrike.com.) Defense: Same as Kerberoasting – secure service account passwords, restrict which accounts can request tickets, and monitor for odd ticket usage.
• DCSync: Abusing the Directory Replication Service (DRS) protocol to simulate a domain controller and request password data. An attacker who has Domain Replication privileges can tell a legitimate DC to replicate AD data to them. Using tools like Mimikatz’s lsadump::dcsync, the attacker can pull password hashes (including the krbtgt hash) directly from a DC without ever touching the DC physically extrahop.comextrahop.com. For example, obtaining the KRBTGT hash via DCSync is often the precursor to a Golden Ticket. Defense: Limit the “Replicating Directory Changes” privilege to as few accounts as possible (ideally, only the DCs themselves). Monitor for abnormal use of the DRSUAPI/DSGetNCChanges call (Windows Security Event 4662 on GUID class of replication), which indicates possible DCSync activity.
• DCShadow: Registering a rogue Domain Controller in order to push fake AD objects into the directory. Introduced in 2018 by Mimikatz, DCShadow lets an attacker add or change AD data by acting as if it were a DC. In practice, the attacker (who needs Admin on a DC) creates a fake server and ntds settings, then uses the Directory Replication Service RPC to write changes to real DCs qomplx.com. Because DCShadow uses the same replication protocols, it can evade many logs; usual Windows event logs do not record these writes. Defense: Monitor DC-to-DC replication traffic closely – any replication request coming from a non-DC machine is suspicious qomplx.com. Use secure LDAP and DRSRM (Require Secure RPC) to protect replication traffic, and audit for unexpected AD changes.
• Other Techniques: AD also has attacks like AS-REP Roasting (exploiting accounts without Kerberos pre-authentication), Overpass-the-Hash (using NTLM hash to request Kerberos tickets), AdminSDHolder abuse (tampering AD ACL inheritance), and Lateral Movement via stolen RDP/SSH/WMIC. While not exhaustively listed here, all involve abusing the AD model. The common thread is that once an attacker has any domain foothold, they map AD paths (often with tools like BloodHound) and exploit trust relationships to gain domain-wide privileges.

In all cases, these AD attacks often go undetected until it is too late cyber.gov.aucyber.gov.au. The worst outcome is requiring drastic recovery measures: an AD compromise may force an organization to reset every password or rebuild the entire forest cyber.gov.au. This is why proactive defense is essential.

Defense Strategies and Best Practices

To protect AD environments, organizations should adopt a multi-layered defense:

• Least Privilege and Tiered Access: Implement Microsoft’s Tier Model so that administrative accounts for servers, domain controllers, and workstations are separated into different privilege tiers. For example, Tier 0 (domain/local AD admins) accounts never log on to Tier 1 or Tier 2 devices. Minimize the number of high-privilege accounts and never put service or user accounts in Domain Admins or Enterprise Admins semperis.comtriaxiomsecurity.com. Use Just-In-Time (JIT) or Privileged Access Management (PAM) solutions to limit standing admin privileges. In general, “don’t log on to high-value servers with accounts that are used elsewhere.”
• Strong Authentication: Enable Multi-Factor Authentication (MFA) on all privileged accounts (and ideally all users). In hybrid environments, use Azure AD Conditional Access to require MFA for sensitive logons cayosoft.com. Disable legacy authentication protocols where possible – turn off NTLM and Windows Digest, and disable weak Kerberos cipher suites (RC4). Newer Windows versions will disable RC4 by default microsoft.commicrosoft.com. Use Group Managed Service Accounts (gMSA) or Managed Service Accounts (MSA) for services so passwords are automatically managed and highly random microsoft.com. Configure all service accounts to use AES encryption for Kerberos tickets and change their passwords immediately after enabling AES microsoft.com.
• Secure Configuration (GPOs and Policies): Enforce strong password policies (length/complexity/expiration) for all AD accounts. Apply account lockout thresholds to slow brute-force. Use Group Policy to disable storage of reversible encryption, disable LM hash storage, and block legacy crypto. Restrict which accounts can log on locally or via RDP/remote management. Do not allow domain admins to have local admin on all servers (use Protected Users group, etc.). Use security baselines (e.g. Microsoft’s recommended security baselines) for DCs and servers. Keep only necessary service accounts, and remove or disable obsolete accounts.
• LAPS (Local Admin Password Solution): Deploy Microsoft LAPS so that each domain-joined machine’s local Administrator password is unique and regularly rotated learn.microsoft.com. This prevents PtH and lateral Pass-the-Ticket across endpoints. LAPS stores each machine’s admin password in AD with strict ACLs. It also can protect DC “Directory Services Restore Mode (DSRM)” passwords. As Microsoft notes, LAPS provides “protection against pass-the-hash and lateral-traversal attacks” learn.microsoft.com.
• Network and DC Hardening: Place DCs in a separate secured network segment. Restrict servers’ ability to initiate outbound connections. Do not use DCs for internet browsing or email. Block all inbound traffic to DCs except required replication and AD protocols. Ensure physical security of DCs and prevent unauthorized hypervisor access. Follow the principle of “AD tiering”: Tier 0 devices (DCs, AD membership servers) should not have direct connectivity to the internet or general user networks.
• Logging, Auditing & Monitoring: Enable advanced audit policies on DCs and critical servers. Audit directory services (4662), logons (4624, 4648), Kerberos ticket operations (4768–4771), and account management (4732–4756). Install Sysmon on servers to get deeper process and network telemetry learn.microsoft.com. Sysmon logs process creations, network connections, and other events that standard Windows logging does not capture. Aggregate logs centrally in a SIEM or monitoring system. Look for signs of AD attacks: unusual Kerberos tickets (long lifetimes or RC4 encryption), multiple service ticket requests from one user, replication events from odd sources microsoft.commicrosoft.com. Tools like Microsoft Defender for Identity (formerly Azure ATP) can automatically analyze domain traffic for suspicious activity (e.g. abnormal process creation on DCs, atypical domain replication, lateral movements) by correlating on-premises and cloud signals learn.microsoft.comlearn.microsoft.com.
• Regular Assessment and Patching: Run AD security scanners (e.g. PingCastle) regularly to find configuration risks medium.com. Keep all Windows servers (especially DCs) fully patched. Update domain functional levels and trust configurations to current versions. Perform penetration tests or purple-team exercises to validate controls. Maintain an updated inventory of all forest trust relationships and DNS trusts; remove any unused trusts.
• Incident Response Preparedness: Develop an AD-specific incident response plan. As CISA/ASD warn, recovering from an AD compromise can require drastic measures (even a full forest rebuild) cyber.gov.au. Have offline backups of DCs and know the Forest Recovery steps (identifying healthy DCs, restoring from backups, etc.) learn.microsoft.com. Periodically practice AD recovery in a lab. Also, proactively change all krbtgt passwords twice periodically (or after any suspected breach) to invalidate stolen Kerberos tickets semperis.com.

Lab Exercises

Lab 1: Basic AD Hardening. Objective: Set up a secure baseline AD environment.

1. Build a Test Domain: Install Windows Server (2022/2019) as the first Domain Controller. Create a new AD forest (e.g. contoso.com). Add a second VM joined to the domain as a member server or workstation.
2. Apply GPO Security Policies: Create and link GPOs to the OU(s) containing user/computer accounts. Enforce strong password policies (e.g. 14+ characters, complexity), account lockout after 5 failures, and disable LAN Manager hash storage. Enable Kerberos pre-authentication for all accounts (avoid accounts with pre-auth off). Disable insecure protocols (e.g. block SMB1, disable NTLM where possible via GPO).
3. Configure LAPS: Download and install the LAPS MSI on the DC. Extend the AD schema for LAPS and deploy LAPS Group Policy (setting the local Administrator password policy). Verify that after GPO refresh, each machine’s local Admin has a unique password in AD.
4. Create Separated Admin Accounts: Set up at least two domain accounts for administration: one “Admin Workstation” account (Tier 1 or 2) and one “Domain Admin” account (Tier 0). Do not use the same account for daily tasks and high privilege tasks. For example, log in to the Admin Workstation VM with a normal user, then use the separate privileged account only when administering AD. Remove the Builtin\Administrator account from any permanent use by adding another unique account to Administrators.
5. Enable MFA: If Azure AD is available, configure Conditional Access to require MFA for all privileged AD logons. For a pure on-prem lab, simulate MFA by adding a RADIUS server for 2FA or use Windows Hello for Business on admin workstations.
6. Test Baseline Tools: Install PingCastle on a management workstation. Run an AD health check (PingCastle.exe –healthcheck) and note the Domain Risk Level and key findings medium.com. Ensure no critical “red” issues remain. (High-scoring issues suggest hardening steps to perform next, such as removing stale users or closing delegation holes.)

Lab 2: AD Attack Simulation. Objective: Demonstrate common AD attacks in a safe lab.

1. Initial Access: On a domain-joined workstation, log in as a regular (low-privilege) user.
2. Dump Credentials: Run Mimikatz (e.g. privilege::debug sekurlsa::logonpasswords) to extract credentials from memory. If you use a privileged account in the session, Mimikatz will reveal its NTLM hash netwrix.com. Save a hash for use.
3. Pass-the-Hash: On an attacker machine (or the same workstation), use a Pass-the-Hash tool (such as pth-winexe or PowerShell’s Invoke-WmiExec) supplying the stolen NTLM hash to authenticate as that user on another machine. Confirm you can access files or run commands on the remote machine without knowing the password.
4. Kerberoasting: Using a tool like Rubeus or PowerShell, enumerate all SPNs in the domain and request service tickets (TGS) for them. Save the tickets to files (e.g. Rubeus kerberoast /export). Use a password-cracking tool (like hashcat) to crack one of the service ticket hashes. You will retrieve the plaintext password of a service account. Verify that account’s privileges (it may be domain admin or backup operator, etc.).
5. Golden Ticket: With Domain Replication rights (or by granting your attacker account DRS perms), use Mimikatz’s DCSync (lsadump::dcsync /user:krbtgt) to obtain the krbtgt NTLM hash extrahop.com. Then use Mimikatz’s Kerberos commands to create a Golden Ticket (kerberos::golden /user:Administrator /domain:CONTOSO /sid:S-1-5-21-... /krbtgt:[hash] /id:500). Inject the ticket (kerberos::ptt). Open a command prompt and run whoami /priv – it should show that you are now DOMAIN\Administrator and can access any resource.
6. DCShadow: On a machine where you have DC admin rights, launch Mimikatz (lsadump::dcsync to ensure you have a DC hash, then lsadump::dcshadow). Configure a fake DC object (Mimikatz will do this). Push a change to AD (e.g. add a new admin user or change a security setting) via the DCShadow replication. Confirm the change appears in AD immediately, even though it did not go through a normal DC.
7. BloodHound Mapping: Install BloodHound (and Neo4j). Use SharpHound or built-in ingestor to collect AD data (users, groups, ACLs) and import into the BloodHound GUI. Visualize the graph to find attack paths from your compromised user to high-value targets (Domain Admin). Note how BloodHound highlights hidden relationships that lead to escalation.

Lab 3: Detection and Mitigation. Objective: Detect the above attacks in logs and mitigate them.

1. Enable Logging: On the domain controller and servers, enable detailed auditing: Kerberos Service Ticket (Event 4769, 4770) and Ticket Granting Ticket (4768, 4771) requests, authentication (4624, 4648), and audit directory replication (4662 on Replication GUID). Install Sysmon on servers to capture process creation and network events learn.microsoft.com. Use a recommended Sysmon config for security (e.g. logging DNS queries, pipe and registry events).
2. Re-run Attacks: Perform a simple attack step (e.g. request a Kerberos ticket for a service account or run Mimikatz). Observe logs:
   • For Kerberoasting, check the Security event log: you should see many Kerberos Ticket events for your user (4769) with Service Name SPNs. In Sysmon logs, note the process that requested klist or network to DC.
   • For Golden Ticket, see that after forging a TGT, Windows will accept it and log your logon (4768) even without contacting a DC.
   • For DCSync/DCShadow, monitor the domain controller: replication events at odd times or from unusual machine names can appear. (Sysmon doesn’t log DCShadow by default, but a network capture might show DRS traffic.)
   • In Microsoft Defender for Identity (if deployed), look for detections like “Golden Ticket suspected” or “Unusual replication” which it can flag.
3. Audit with Tools: Run PingCastle or Purple Knight after the lab attacks. The scan may flag issues like “too many members in Domain Admins” or “DS-Rep-Rights granted” or “AdminSDHolder risks”. Investigate and fix these issues.
4. Mitigation:
   • If Golden Ticket was generated, execute net user krbtgt * twice on the DC to reset KRBTGT’s password, invalidating the forged tickets semperis.com.
   • For Kerberoasting, change the password of any cracked service account to a long, random one, and disable RC4 encryption on its account microsoft.commicrosoft.com. If possible, convert the service to use a gMSA.
   • Remove any unauthorized accounts or changes injected by DCShadow (use AD change logs or backups).
   • Verify that legacy accounts or trust paths exploited in the lab (as shown by BloodHound) are closed: remove unnecessary group memberships and harden ACLs.

By completing these labs, learners see how AD attacks are executed and how vigilant monitoring (event logs, Defender for Identity) and proactive policies (LAPS, tiering, MFA) can prevent or detect them.

Tools for Securing and Auditing AD

• PingCastle: An open-source AD assessment tool. It performs a “health check” of the domain and produces an HTML report with an overall Domain Risk Score medium.com. The report highlights issues in four areas (Privileged Accounts, Trusts, Stale Objects, Security Anomalies) and gives remediation advice for each finding medium.com. PingCastle can also generate a visual AD map of domain trust and OU relationships (see below). In practice, administrators download PingCastle, run the executable, and review the output report for critical issues to fix medium.com.

Figure: Example PingCastle “Active Directory map” of a domain. Node colors indicate domain risk scores (green=good, red=high risk).

• BloodHound: A graph-based AD analysis tool for both attackers and defenders sans.org. BloodHound ingests data from AD (using a collector like SharpHound) and shows all user/group/ACL relationships. It then computes the shortest paths an attacker could take to reach high-value targets. Blue teams use BloodHound to visualize hidden privilege paths and fix them. (As SANS notes, BloodHound “focuses on the ones that an attacker may abuse” sans.org.)
• Local Administrator Password Solution (LAPS): A Microsoft feature (now built-in to Windows) that automatically rotates and stores each computer’s local Administrator password in AD learn.microsoft.com. By eliminating static local Admin passwords, LAPS defeats Pass-the-Hash attacks on endpoints. Microsoft confirms LAPS “provides protection against pass-the-hash and lateral-traversal attacks” learn.microsoft.com. In labs and production, deploying LAPS is as simple as installing the GPO/Management Client and configuring a policy; admins then retrieve passwords securely from AD when needed.
• Sysmon (System Monitor): A free Sysinternals driver/service for detailed event logging. Sysmon logs process creation (with full command line), network connections, file modifications, and more learn.microsoft.com. Unlike standard Windows logs, Sysmon can record an attacker’s malicious process or unusual network connections (e.g. a suspicious LDAP query). Security teams collect Sysmon events in their SIEM to detect lateral movement or credential dumping (for example, a high-privilege account spawning Mimikatz would be captured).
• Microsoft Defender for Identity: A cloud service (formerly Azure ATP) that monitors on-prem AD traffic and cloud identity signals. It analyzes account behavior and raises alerts for suspicious actions like Pass-the-Hash, Kerberoasting, DCSync, Golden Ticket, and unusual logons learn.microsoft.comlearn.microsoft.com. Defender for Identity provides pre-built detections (e.g. “Filtered Attacks: DC Sync” or “Unusual Service Tickets”) and actionable reports. In hybrid setups, it correlates on-prem AD detections with Azure AD identity risk signals, giving SecOps teams a unified view of identity threats.
• Additional Tools: Other useful tools include Azure AD Connect Health (monitors AD synchronization health) cayosoft.com, Purple Knight (Semperis’s free AD security scanner), and SIEM solutions with built-in AD threat rules. PowerShell cmdlets (e.g. Get-ADUser, Get-ADObject -Filter * -SearchBase, etc.) can also audit AD configuration. Windows Event subscriptions and Azure Sentinel/Defender can collect logs across the hybrid environment.

Hybrid AD (Azure AD) Security

Many organizations run hybrid identity with on-prem AD and Azure Active Directory (Azure AD). Security in this scenario involves both sides:

• Azure AD Connect & Sync: Ensure Azure AD Connect is running the latest version and uses Secure Sync. Use Azure AD Connect Health to monitor sync status, DC health, and replication security cayosoft.com. Limit Azure AD Connect permissions to just the sync operations and use a dedicated service account with minimal rights.
• Conditional Access & MFA: Enforce Conditional Access policies in Azure AD to require MFA or device compliance for access to cloud apps and synchronized identities. For example, require MFA when signing in as a Privileged Authentication Administrator or for risky sign-ins. Protect sync accounts with smartcard or FIDO2 (Windows Hello for Business). As Cayosoft recommends, “employ authentication methods such as Conditional Access policies and MFA for both on-premises and cloud” cayosoft.com.
• Identity Protection: Use Azure AD Identity Protection to detect compromises in cloud identities (like sign-ins from unusual locations or malware-linked IPs). Enable Privileged Identity Management (PIM) for Azure roles to grant admins just-in-time Azure privileges. Integrate Defender for Identity so on-prem and Azure AD risk alerts feed into one portal.
• Single Sign-On (SSO) and Federation: If using AD FS or pass-through auth, secure the ADFS servers and ensure tokens are validated. Monitor federation logs for anomalies. Enforce modern auth on cloud apps.
• Cross-Environment Visibility: A hybrid AD breach often spans both on-prem and cloud. Tools like Microsoft Sentinel or other SIEMs can ingest Azure AD audit logs (sign-ins, risk detections) alongside on-prem logs. Ensure conditional access policies do not allow legacy auth or untrusted clients.

In essence, treat identity as the security perimeter – focus on protecting user sign-in and Azure AD configurations learn.microsoft.comcayosoft.com. Properly syncing and securing Azure AD extends on-prem protections to the cloud (and vice versa), reducing the risk that an attacker can leverage one side to compromise the other.

Incident Response and Recovery

If an AD compromise is suspected or detected, a well-defined response plan is vital:

1. Detect and Scope: Use alerts (e.g. Defender for Identity or SIEM alarms) to confirm compromise. Identify affected accounts, machines, and DCs. Disconnect compromised systems from the network if needed.
2. Contain: Secure the environment by disabling backdoor accounts, revoking active sessions (e.g. kill RDP/SSH sessions), and isolating the domain. Ensure that DCs are air-gapped or booted offline to prevent further malicious changes. Change all smartcard PINs or MFA devices used by the attacker.
3. Account Remediation: Immediately change the passwords of all known compromised accounts (users and service accounts). Crucially, reset the KRBTGT password twice to invalidate any Golden Tickets semperis.com. Also reset the DSRM password and any backup operator credentials.
4. Investigate: Perform forensic analysis of logs (Windows Event Logs, Sysmon data, Netlogon logs). Determine the attack vector (e.g. what allowed initial access and how privileges were escalated). Identify all actions the attacker took (creating accounts, modifying ACLs, etc.). Use backups to verify what changes were malicious.
5. Recovery: If AD itself is deeply compromised, consider Forest Recovery. Follow Microsoft’s AD Forest Recovery steps learn.microsoft.com:
   • Identify the problem: Engage Microsoft support. Decide if partial or full recovery is needed.
   • Recover one DC per domain: In a safe network (no trust to original environment), restore a bare-metal backup of a DC that is known-good, or cleanly rebuild a DC using AD backup data. Reset all privileged credentials during recovery.
   • Rebuild the forest: Once one DC per domain is recovered, bring up additional DCs and rebuild services (DNS, etc.). Remove any compromised objects before reintroducing.
   • Cleanup: Fix DNS settings, rejoin domain-joined machines, and test authentication thoroughly.
   (Note: If no clean backup exists, an “authoritative forest restore” from snapshots or last known good data may be needed – but this is very advanced.)
6. Post-Mortem: After restoring functionality, audit every aspect of AD configuration. Tighten any weaknesses that were exploited. Conduct a lessons-learned review. Update incident response and recovery plans accordingly. As the ASD/CISA guide warns, “Responding to and recovering from malicious activity involving Active Directory compromise is often time consuming, costly, and disruptive.” The best “response” is to be ready for it (e.g. have tested forest recovery and regularly rotate keys) cyber.gov.aulearn.microsoft.com.

By following these steps, an organization can isolate and eradicate an AD breach. It’s worth remembering Microsoft’s advice: plan for compromise. No defense is perfect, so having backups and a forest recovery plan in place before disaster strikes is the surest way to minimize downtime and data loss learn.microsoft.comlearn.microsoft.com.

In summary: Active Directory security demands layered defenses, continuous monitoring, and preparedness. Clear understanding of AD concepts, vigilant hardening (GPOs, LAPS, MFA, least privilege), and knowledge of how attacks work (Kerberoasting, PtH, Golden Tickets, etc.) are all essential. Regular use of auditing tools (PingCastle, BloodHound, Defender for Identity) helps spot weaknesses early medium.comlearn.microsoft.com. Finally, have a practiced incident response plan. With these measures, organizations can greatly reduce the risk that an AD compromise cripples their entire network.

Sources: Authoritative Microsoft documentation and cybersecurity research (see citations) were used to explain AD components, attacks, defenses, and procedures learn.microsoft.comsentinelone.comcyber.gov.aunetwrix.comsemperis.comextrahop.comqomplx.comtriaxiomsecurity.comlearn.microsoft.comlearn.microsoft.comcayosoft.comlearn.microsoft.comlearn.microsoft.commicrosoft.com, among others, ensuring up-to-date and accurate guidance.