Listen to this Post
Abdullah Al Shahid Chowdhury recently completed two intensive courses: “Getting Started in ICS/OT Cyber Security” and “OSINT for ICS/OT.” These programs provided hands-on training in critical industrial control systems (ICS) and operational technology (OT) security skills, including:
🔹 Network traffic analysis with Wireshark
🔹 Secure architecture design using the Purdue Model
🔹 Asset register creation for ICS/OT environments
🔹 OSINT techniques with tools like Shodan, hunter.io, and DNSlytics
You Should Know: Practical ICS/OT Security Commands and Techniques
1. Wireshark for ICS/OT Traffic Analysis
Wireshark is essential for monitoring ICS/OT network traffic. Key commands:
wireshark -k -i eth0 -Y "modbus" Capture Modbus traffic tshark -r ot_capture.pcap -Y "dnp3" -w dnp3_traffic.pcap Filter DNP3 traffic
Practice Tip: Use display filters like `modbus || dnp3 || opcua` to isolate industrial protocols.
2. Shodan for ICS/OT Device Discovery
Shodan helps identify exposed OT devices. Try these queries:
shodan search 'port:502 product:modbus' Find Modbus devices shodan search 'title:"Schneider Electric" port:102' Siemens S7 devices
Pro Tip: Use API automation:
import shodan
api = shodan.Shodan('API_KEY')
results = api.search('port:161 SNMP')
3. DNSlytics for Threat Intelligence
Investigate domain reputations:
curl "https://dnslytics.com/api/v1/report/domain/example.com"
4. Purdue Model Segmentation
Enforce network segmentation using firewall rules (Linux example):
iptables -A FORWARD -p tcp --dport 502 -j DROP Block external Modbus iptables -A FORWARD -s 192.168.1.0/24 -d 10.0.0.0/8 -j ACCEPT Allow OT-to-IT
5. Asset Inventory with Nmap
Scan OT networks carefully:
nmap -sT -Pn -T4 -p 1-1024 --script modbus-discover 192.168.1.0/24
What Undercode Say
ICS/OT security demands protocol expertise (Modbus, DNP3), passive reconnaissance (Shodan), and strict segmentation. Mastery of Wireshark, Nmap, and firewall rules is non-negotiable. Always validate findings in a lab before live deployment.
Expected Output:
- Filtered Modbus traffic in Wireshark (
modbus.func_code == 3). - Shodan results exposing unsecured PLCs.
- Firewall logs blocking unauthorized OT access.
References:
References:
Reported By: Shahidaac Otsecurity – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
