What is OT security?

OT security, or operational technology security, is the practice of protecting the hardware and software systems that control and monitor physical processes in industrial environments. Unlike traditional information technology (IT) security, which prioritizes the confidentiality, integrity, and availability (the CIA triad) of data, OT security focuses on the safety and continuous availability of physical operations. These systems are critical to sectors like manufacturing, energy, transportation, and utilities, where a cyberattack could lead to equipment damage, environmental harm, or endanger human lives.

What is operational technology (OT)?

Operational technology (OT) refers to the computing systems used to manage and control physical devices and processes. Examples of OT include industrial control systems (ICS), such as Supervisory Control and Data Acquisition (SCADA) systems, Distributed Control Systems (DCS), and Programmable Logic Controllers (PLCs). OT security is the cybersecurity discipline dedicated to safeguarding these systems from cyber threats. The goal is to ensure the reliability, availability, and safety of the industrial processes these technologies oversee.

Why is OT security critical?

The importance of OT security has grown exponentially with the convergence of IT and OT networks. Historically, OT environments were "air-gapped," meaning they were physically isolated from the internet and corporate IT networks, providing a natural defense. However, the push for greater efficiency, data analytics, and remote access has connected these systems, exposing them to the same cyber threats that plague IT.

A successful attack on an OT system can have devastating real-world consequences, including:

• Physical damage: Malicious actors can manipulate industrial processes to cause equipment to fail, leading to explosions, fires, or other destructive outcomes.
• Service disruption: Attacks can shut down power grids, water treatment plants, or manufacturing lines, causing widespread service outages and economic loss.
• Environmental harm: A breach could lead to the release of hazardous chemicals or other pollutants, causing significant environmental damage.
• Safety risks: Compromised systems can override safety mechanisms, putting workers and the public at risk.

OT security best practices

Securing an OT environment requires a unique, multi-layered approach. Practitioners should focus on the following key strategies:

• Asset discovery and inventory: You can't protect the assets you don't know you have. Attack surface management, including a complete and accurate inventory of all devices, their configurations, and their network connections, is the essential first step.
• Network segmentation: Use the Purdue Model (discussed below) as a guide to segment OT networks from IT networks and critical systems from less critical ones. This containment strategy helps limit lateral movement in the event of a breach.
• Robust access control: Implement the principle of least privilege, ensuring that users and devices only have the minimum access necessary to perform their functions. Use strong authentication methods, including multi-factor authentication (MFA), especially for remote access.
• Secure remote access: All remote connections to the OT network should be strictly controlled and monitored. A zero-trust security architecture, which requires continuous verification of every user and device, is a powerful approach.
• Continuous monitoring and visibility: Deploy solutions that provide deep visibility into network traffic and asset behavior within the OT environment. This allows security teams to detect anomalies and respond to threats in real-time.
• Incident response plan: Develop a comprehensive incident response plan specifically for the OT environment. This plan should outline clear roles, responsibilities, and communication protocols for responding to and recovering from a cyberattack.

OT security risks & challenges

The unique nature of OT environments presents a number of significant challenges for security practitioners:

• Legacy systems: Many OT systems were designed before modern cybersecurity was a concern. They may run on outdated operating systems, lack built-in security features, and cannot be patched without significant disruption.
• Availability vs. security: The primary mission of OT is to keep the lights on and the processes running. This can create a conflict with IT-centric security measures that might cause downtime, such as patching or system reboots.
• Unique protocols: OT networks often use proprietary and non-standard communication protocols that traditional IT security tools can't understand or inspect.
• Lack of visibility: Many organizations have a poor understanding of what is happening on their OT networks. They lack the tools to see connected devices, map communication flows, or detect unauthorized changes.
• Physical security: While cybersecurity is a major concern, OT systems are also vulnerable to physical attacks. Unauthorized physical access to a PLC or sensor can be as damaging as a remote cyberattack.

How Corelight Open NDR platform provides deep visibility and defense for OT networks

A crucial part of any modern OT security strategy is Network Detection and Response (NDR). Solutions like Corelight's Open NDR Platform provide deep visibility into network traffic across both IT and OT environments, helping to overcome the "air-gap" myth and the blind spots of legacy systems.

The Corelight Open NDR Platform provides deep and comprehensive network visibility, which is essential for protecting devices outside the traditional IT scope. Given that many OT protocols are unauthenticated and unencrypted, visibility becomes a primary security control. Corelight's platform leverages the open-source Zeek network security monitoring framework and includes a dedicated ICS/OT Collection of protocol analyzers. This collection supports a wide range of common OT protocols, such as BACnet, DNP3, Modbus, and PROFINET, allowing security teams to gain awareness and visibility into these networks.

By analyzing this network traffic, Corelight enables security teams to validate network segmentation, and identify, understand, and manage additional risks associated with industrial control systems and critical infrastructure devices. This visibility supports multiple use cases, including creating an accurate device inventory, monitoring network behavior to detect anomalies (like an HVAC system communicating with a payroll server), and providing forensic-quality evidence for incident response. Corelight makes it easy to see how controllers and devices interact. The platform helps security professionals mitigate the risks posed by these critical, yet often unmanaged, devices. The rich telemetry Corelight provides allows security teams to detect attacks that evade traditional signature-based tools, accelerate incident response by providing forensic-quality evidence, and validate the effectiveness of security controls without disrupting critical operations.

Additionally, this capability directly aids in achieving compliance with major OT security frameworks. For instance, the detailed logs and asset identification support the identify function of the NIST Cybersecurity Framework (CSF) and the robust asset inventory requirements of NERC CIP. By continuously monitoring network behavior and providing forensic-quality evidence, Corelight helps organizations meet the detect and respond mandates of frameworks like the ISA/IEC 62443 series and provides the necessary audit trails and threat intelligence needed for regulatory adherence like EU NIS2 and the security controls outlined in NIST SP 800-82.