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Introduction:
Operational Technology (OT) and Industrial Control Systems (ICS) have become prime targets for nation‑state actors and ransomware syndicates, yet the workforce remains divided between sales teams that cannot articulate risk and engineers who lack strategic context. Mike Holcomb’s recently highlighted 11‑part, 20+ hour course bridges this divide by delivering both the technical nuts‑and‑bolts of Purdue Model layers and the business‑level narratives required to sell or secure industrial environments. This article extracts the course’s core technical pillars, translates them into executable commands and configuration audits, and provides a roadmap for sales professionals and delivery engineers to speak the same security language.
Learning Objectives:
- Map OT/ICS attack surfaces using passive and active reconnaissance techniques common in adversary toolkits.
- Implement foundational security controls across Windows‑based HMIs and Linux‑based PLC engineering workstations.
- Harden industrial network segments with firewall rules and switch port security tailored to proprietary ICS protocols.
You Should Know:
1. Network Topology Discovery in Air‑Gapped OT Environments
Modern ICS attacks often begin with physical access to a laptop or a compromised vendor laptop. Before any sensor deployment, defenders and penetration testers must understand the live topology without disrupting production.
Step‑by‑step guide – Passive asset discovery on a shadow IT switch:
Linux: Use arp‑scan and tcpdump to identify live hosts without sending noisy probes sudo arp‑scan --localnet --interface eth0 sudo tcpdump -i eth0 -n ’port 47808’ BACnet/IP often present in building management systems
For Windows environments where Wireshark is permitted:
:: Run as Administrator on a mirrored port
net start npf Start Npcap driver
tshark -i \Device\NPF_{GUID} -Y "cip or enip or modbus" Filter common industrial protocols
What this does: It silently builds a list of IP‑enabled controllers, HMIs, and historians. Sales teams can use this output to demonstrate the “unknown asset” problem; engineers use it to update configuration management databases.
2. Windows Hardening for HMI / Engineering Workstations
Most HMIs run Windows 10 IoT or Server 2016/2019 with local admin accounts and outdated application whitelisting.
Step‑by‑step guide – Applying CIS benchmarks to an HMI:
Disable SMBv1 – still rampant in ICS Set‑SmbServerConfiguration -EnableSMB1Protocol $false -Force Enable PowerShell logging for forensics New‑ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" ` -Name "EnableScriptBlockLogging" -Value 1 -PropertyType DWord -Force Remove local admin rights from interactive users Remove‑LocalGroupMember -Group "Administrators" -Member "OPERATOR\hmiuser"
Tutorial: Combine these with AppLocker rules (via GPO) that only allow signed Siemens, Rockwell, or Wonderware binaries. Sales professionals can cite this as “preventing ransomware from encrypting the operator interface.”
- Securing Proprietary ICS Protocols at the Network Edge
Modbus/TCP, EtherNet/IP, and Profinet lack authentication. Attackers who reach the control VLAN can issue STOP commands to motors or open breakers.
Step‑by‑step guide – ACLs on a Cisco IE 4000 switch:
configure terminal ip access‑list extended PROTECT-PLC deny tcp any any eq 502 ! Block rogue Modbus clients deny udp any any eq 2222 ! EtherNet/IP explicit messaging permit ip any any interface vlan 10 ip access‑group PROTECT-PLC in
On a Linux‑based industrial firewall (e.g., Tofino or open source iptables):
Drop all Modbus writes except from the primary HMI iptables -A FORWARD -p tcp --dport 502 -m string --algo bm --string ’\x00\x00\x00\x00\x00\x06\x01\x05’ -j DROP
Explanation: The hex pattern matches a Modbus coil write command. Only the specific engineering station IP should be allowed to send such patterns.
4. Vulnerability Prioritisation for ICS‑Specific CVEs
Generic IT CVSS scores often misrepresent risk in OT (e.g., a high‑availability PLC crashing from a low‑complexity DoS).
Step‑by‑step guide – Using `plcscan` and `nmap` to identify exposed Siemens S7‑1200:
git clone https://github.com/meeas/plcscan.git python3 plcscan.py —hosts 10.10.10.0/24 —timeout 2 Validate with nmap script nmap -p 102 —script s7-info.nse 10.10.10.10-20
If a device returns firmware < 4.5, it is vulnerable to CVE‑2020‑15782 (crash via crafted packet). Recommended mitigation: deploy an IPS signature that blocks TPKT fragmentation to that PLC.
5. Centralised Logging for Forensics and Compliance
Many sites still rely on local event logs that roll over weekly.
Step‑by‑step guide – Forwarding Windows event logs to a Linux SIEM (Wazuh/ELK):
Install Winlogbeat winlogbeat.exe setup -e
winlogbeat.yml excerpt winlogbeat.event_logs: - name: Application - name: Security - name: System - name: Siemens/WinCC Custom logs output.logstash: hosts: ["192.168.1.100:5044"]
For Linux‑based PLC engineering stations:
Use syslog‑ng to forward Rockwell Logix diagnostics
source s_plc { file("/var/log/plc/diagnostics.log"); };
destination d_siem { syslog("192.168.1.100" transport("tcp")); };
log { source(s_plc); destination(d_siem); };
6. Simulating an ICS Incident Response Playbook
Sales and delivery teams must understand what happens when “deny all” is triggered.
Step‑by‑step guide – Tabletop simulation using a virtual PLC environment:
Deploy OpenPLC on Ubuntu for testing sudo apt install openplc sudo systemctl start openplc Simulate unauthorised write via Modbus modbus client 127.0.0.1 -t 0 -r 100 1 Write coil 100 = ON
The response: immediately isolate the switch port using SNMP:
snmpset -v2c -c private 192.168.1.2 1.3.6.1.2.1.2.2.1.7.1 i 2
This command disables port 1 on the managed switch, mirroring a real‑world containment action.
What Undercode Say:
Key Takeaway 1: OT/ICS cybersecurity is no longer solely an engineering discipline. Sales professionals who understand packet‑level protocol weaknesses can articulate risk in boardroom terms, accelerating both buy‑in and budget.
Key Takeaway 2: The most effective course content integrates live command examples. Holcomb’s curriculum moves beyond slides by embedding the exact commands and checks that uncover shadow IT, weak access controls, and outdated firmware—turning theory into billable deliverables.
+ analysis around 10 lines:
The post and its viral reaction reveal a hungry market segment: professionals caught between legacy industrial inertia and modern threat landscapes. By open‑sourcing this level of technical depth, the community normalises proactive defence over reactive patching. The inclusion of both passive scanning and active ACL deployment reflects a mature understanding that OT security is a spectrum, not a binary state. Sales teams leveraging this knowledge no longer sell “security products”; they sell operational continuity. The course’s length (20+ hours) signals that there are no shortcuts—organisations serious about resilience must invest in sustained education, not one‑hour webinars.
Prediction:
As industrial cyber insurance carriers begin requiring documented training like Holcomb’s, we will see a sharp rise in “technical sellers”—sales engineers who can demonstrate hands‑on configuration of firewalls and endpoint detection. This shift will blur the line between pre‑sales and post‑sales delivery, leading to hybrid roles that command 25–40% higher compensation. Within three years, foundational ICS protocol analysis will be a baseline requirement for any enterprise account executive targeting manufacturing or critical infrastructure.
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Reported By: Paul Panepinto – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
