OT Cybersecurity Fundamentals
Operational Technology (OT) keeps production lines, moving, water flowing, and lights on, yet most cybersecurity pros defend Information Technology (IT). As ransomware attacks and advanced adversaries target OT, new skills are needed to safeguard critical infrastructure.
OT cybersecurity protects operational technology systems that control physical processes in industrial environments. Unlike IT security, OT cybersecurity prioritizes operational continuity and safety, focusing on protecting critical infrastructure like manufacturing plants, power grids, and water treatment facilities from cyber threats.
IT-OT convergence has many forms. It’s OT devices running on the same IT operating systems; it’s integrating access, alerts, & other processes to gain efficiencies; it’s leveraging newer technologies like IoT and mobile networks to better optimize operation. This convergence connects previously isolated industrial systems to corporate networks, creating connectivity benefits while introducing cybersecurity risks that require specialized approaches.
Key ICS components include programmable logic controllers (PLCs) for process control, human-machine interfaces (HMIs) for operator visualization, supervisory control and data acquisition (SCADA) systems for remote monitoring, distributed control systems (DCS) for large-scale process control, and remote terminal units (RTUs) for field device communication. ICS systems include electricity production and distribution, water systems, pipeline and refining systems among many others.
To secure Operational Technology (OT), IT professionals must understand its unique hardware and software components: PLCs provide real-time control with limited security features, HMIs serve as operator interface panels, SCADA systems function as process command centers, and industrial protocols like Modbus, DNP3, and EtherNet/IP prioritize speed and reliability over security. They should understand the key assets or crown jewels of the OT processes, the attack paths, and the scenarios attackers would take to inform their planning.
IT professionals often apply inappropriate security tools that can disrupt operations, such as vulnerability scanners that cause PLC faults or network monitoring tools that flood industrial networks. Other common mistakes include treating OT like IT with frequent patching cycles, focusing only on network perimeter security while ignoring internal segmentation, and underestimating the operational impact of security controls. Successful OT security requires understanding operational constraints, using passive monitoring techniques, and coordinating closely with operations teams
Basic OT visibility and monitoring can be established in 30-90 days depending on network complexity. Complete implementation of the SANS ICS 5 Critical Controls can take anywhere between 2-18 months. You can implement the basics of the SANS ICS critical controls quickly with the right resources and help, then work towards operationalization of critical processes and tooling.
OT security requires specialized approaches because standard IT tools can cause operational disruptions. OT systems use specialized protocols to communicate that OT specialist attackers understand, but IT tools don’t. Vulnerability scans can fault PLCs, patches often require costly production shutdowns, and security patches can’t be applied to live processes with distant maintenance windows. Major incidents like Stuxnet and Ukraine grid attacks demonstrate these risks. Effective OT security understands OT systems and protocols, uses passive monitoring & selective active queries during scheduled maintenance windows, and operationally-aware controls that won’t impact production
