Active Directory (AD) is a critical security component for managing Windows-based systems, which are prevalent in both IT and Operational Technology (OT)/Industrial Control Systems (ICS) environments. However, integrating IT AD with OT/ICS AD is a severe security risk.
Key Reasons to Keep IT and OT AD Separate:
1. Prevents Lateral Movement – Attackers who compromise IT AD can pivot to OT systems if trusts exist.
2. Different Security Policies – OT systems often require stricter controls, specialized Group Policies, and unique password policies.
3. Reduces Attack Surface – Isolating OT AD ensures that IT breaches don’t automatically endanger critical infrastructure.
Best Practices for OT/ICS Active Directory:
✔ Deploy a Separate AD Forest – Maintain a dedicated OT AD with no trusts to IT AD.
✔ Enforce Strong Password Policies – OT systems should have longer, more complex passwords.
✔ Disable Unnecessary Services – Turn off Kerberos, LDAP, or RPC if not needed in OT.
✔ Monitor & Log All AD Changes – Use tools like Microsoft Defender for Identity or Splunk for anomaly detection.
You Should Know: Hardening OT Active Directory
1. Disable Risky Protocols
OT AD should restrict protocols like:
Disable SMBv1 (Critical for OT Security) Disable-WindowsOptionalFeature -Online -FeatureName smb1protocol Disable NTLM (Use Kerberos only where necessary) Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" -Name "LmCompatibilityLevel" -Value 5
2. Implement Network Segmentation
Use firewalls to block traffic between IT and OT AD:
Example iptables rule to block IT-to-OT traffic iptables -A FORWARD -s 192.168.1.0/24 -d 10.0.0.0/24 -j DROP
3. Enable Enhanced Logging
Configure OT AD to log all authentication attempts:
Enable detailed auditing in Group Policy auditpol /set /subcategory:"Logon" /success:enable /failure:enable
4. Use Dedicated Admin Accounts for OT
Never reuse IT admin credentials in OT:
Create an OT-specific admin account New-ADUser -Name "OT_Admin" -AccountPassword (ConvertTo-SecureString "Str0ngP@ss!" -AsPlainText -Force) -Enabled $true Add-ADGroupMember -Identity "Domain Admins" -Members "OT_Admin"
5. Regularly Patch OT Domain Controllers
OT systems often lag in updates, but AD must be secured:
Check for pending updates on Windows OT servers wuauclt /detectnow /updatenow
What Undercode Say
Merging IT and OT Active Directory is a catastrophic risk. Attackers routinely exploit AD trusts to move from corporate networks to critical infrastructure. By maintaining separate forests, enforcing strict policies, and disabling unnecessary protocols, organizations can significantly reduce exposure.
Expected Output:
✅ OT AD is isolated from IT AD with no trusts.
✅ All OT AD changes are logged and monitored.
✅ Dedicated OT admin accounts with strong passwords.
✅ Network segmentation prevents IT-to-OT lateral movement.
Stay secure. Isolate. Monitor. Defend.
Prediction: As OT/ICS attacks rise, regulatory bodies will mandate complete AD separation for critical infrastructure within 3 years. Companies ignoring this will face breaches.
References:
Reported By: Https: – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
