Industrial Control System (ICS) Security

Industrial Control Systems encompass a broad range of technologies including Supervisory Control and Data Acquisition (SCADA) systems, Distributed Control Systems (DCS), Programmable Logic Controllers (PLCs), Remote Terminal Units (RTUs), and Human-Machine Interfaces (HMIs). These systems control physical processes — opening valves, adjusting temperatures, managing electrical loads — and a security breach can result in equipment damage, environmental catastrophe, or loss of life.

Historically, ICS networks were air-gapped from corporate IT networks and the internet, operating on proprietary protocols. The convergence of IT and OT (Operational Technology) networks, driven by efficiency demands and the Industrial IoT, has dramatically expanded the attack surface. Legacy protocols such as Modbus, DNP3, and OPC Classic were designed without authentication or encryption, making them vulnerable to spoofing and replay attacks when exposed to untrusted networks.

Notable ICS attacks include Stuxnet, which targeted Iranian nuclear centrifuges through PLC manipulation, the Ukraine power grid attacks of 2015 and 2016, and the Triton/TRISIS malware that targeted safety instrumented systems. These incidents demonstrate that ICS attacks can have kinetic real-world consequences far beyond data theft.

Effective ICS security requires network segmentation using industrial demilitarised zones (DMZs) between IT and OT networks, continuous asset inventory and vulnerability management for OT devices, deployment of OT-specific intrusion detection systems, adherence to standards like IEC 62443 and NIST SP 800-82, and establishing incident response procedures tailored to operational environments where simply shutting down systems may not be an option.