Listen to this Post
Introduction
Operational Technology (OT) and Industrial Control Systems (ICS) security is a critical yet often misunderstood field. Unlike traditional IT penetration testing, OT pentesting requires specialized knowledge to avoid disrupting critical infrastructure. This article explores key concepts from Mike Holcomb’s sold-out OT/ICS penetration testing course, providing actionable insights, commands, and methodologies for safely assessing industrial environments.
Learning Objectives
- Understand the key differences between IT and OT penetration testing.
- Learn safe techniques for assessing OT/ICS environments.
- Gain hands-on experience with OT-specific tools and methodologies.
You Should Know
1. Pivoting from IT to OT: Reconnaissance Differences
Command (Nmap for OT Networks):
nmap -Pn -sT --script=banner -p 502,102,44818,1911 <OT_IP_Range>
What It Does:
Scans common OT protocols (Modbus, Siemens S7, EtherNet/IP) without aggressive probing (-Pn avoids host discovery, `-sT` uses TCP connect scan).
Step-by-Step Guide:
- Identify the OT network segment (isolated from IT).
- Use passive reconnaissance tools like Shodan (
shodan search port:502) to find exposed PLCs.
3. Limit scan intensity to avoid disrupting devices.
- Safe OT Penetration Testing: The “No Crash” Rule
Tool (PLCScan for Device Fingerprinting):
python plcscan.py -i <PLC_IP> -p 102
What It Does:
Identifies Siemens S7 PLCs without sending malformed packets that could trigger faults.
Step-by-Step Guide:
1. Always test in a lab environment first.
- Avoid denial-of-service (DoS) exploits—OT devices often lack redundancy.
- Use vendor-approved tools like Wireshark OT plugins for traffic analysis.
3. Attacking OT Assets: PLC Exploitation
Metasploit Module (Modbus Command Injection):
use auxiliary/scanner/scada/modbusclient set RHOSTS <PLC_IP> run
What It Does:
Tests for unauthorized Modbus command execution, a common OT vulnerability.
Step-by-Step Guide:
- Gain network access (e.g., via phishing or IT-to-OT pivot).
2. Use modbus-cli to read/write PLC registers:
modbus read --ip=<PLC_IP> --address=0 --count=10
3. Never write to registers without approval—could halt production.
4. Assumed Breach: IT/OT DMZ Pivoting
Tool (Covenant C2 for Lateral Movement):
Invoke-Command -ComputerName <OT_Gateway> -ScriptBlock {whoami}
What It Does:
Simulates an attacker moving from IT to OT via poorly segmented DMZs.
Step-by-Step Guide:
- Compromise an IT workstation with Covenant or Cobalt Strike.
2. Use PowerShell Remoting to probe OT gateways.
3. Document segmentation failures for remediation.
5. Impacting Industrial Processes: HMI Exploits
Exploit (CVE-2020-6969 for Siemens HMI):
python2 siemens_hmi_rce.py -t <HMI_IP> -c "reboot"
What It Does:
Demonstrates how unpatched HMIs can disrupt operations.
Step-by-Step Guide:
1. Patch HMIs offline—never during production.
- Monitor for abnormal HMI traffic with Snort OT rules:
snort -c /etc/snort/ot.rules -i eth0
6. Writing an OT Pentest Report
Template Structure:
1. Executive Summary (risk to safety/operations).
2. Methodology (tools used, safety precautions).
3. Findings (ranked by impact, not CVSS).
4. Mitigations (vendor-specific patches, network segmentation).
What Undercode Say
- Key Takeaway 1: OT pentesting prioritizes safety over exploitation—unlike IT, a single crash can halt a plant.
- Key Takeaway 2: Assume breach scenarios reveal IT/OT convergence risks; segmentation is critical.
Analysis:
The rise of IT/OT convergence demands hybrid pentesters who understand both worlds. Attacks like Triton malware (targeting safety systems) show OT’s unique risks. Future regulations will likely mandate OT-specific testing frameworks, making courses like Holcomb’s essential for defenders.
Prediction
By 2025, OT pentesting will become a compliance requirement for critical infrastructure, driven by incidents like Colonial Pipeline. Expect more open-source OT tools (similar to Metasploit ICS modules) and specialized certifications.
Ready to dive deeper? Enroll in Mike Holcomb’s course here or explore his newsletter here.
For more commands, lab setups, or OT security discussions, comment below or share this article with your network!
IT/Security Reporter URL:
Reported By: Https: – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
