Digitalization initiatives and the expansion of remote workforces have transformed enterprises, causing once-isolated operational technology (OT) environments to become interconnected with their information technology (IT) counterparts. The result is the rise of converged IT/OT networks that offer great opportunities to enhance innovation and efficiencies within industrial environments.
Despite the clear benefits of cyber-physical connectivity, it creates an expanded attack surface across a host of unique and unfamiliar device types, communicating with often proprietary protocols which render traditional IT security solutions unsuitable for protection. As a result, critical infrastructure organizations require specific industrial cybersecurity tactics, such as OT network monitoring, to protect their unique environments.
OT Network Monitoring in Industrial Environments
In industrial environments, OT network monitoring involves continuous supervision of an organization’s assets and infrastructure including supervisory control and data acquisition (SCADA systems), industrial control systems (ICS), building automation systems (BAS), and other devices to maintain performance, ensure availability, and safeguard against cyber threats.
To make this possible, organizations first need to know what assets are located in their environment. However, OT assets require a unique approach to discovery compared to IT assets. Let’s dive into the differences between the two and the unique requirements to protect them.
Difference Between IT and OT Networks
IT systems are primarily used for the storage and processing of data, while OT systems control physical processes and systems. Examples of IT systems include servers, computers, software applications, and databases. While examples of OT systems include ICS, sensors, robotics, and other physical devices used in critical infrastructure industries.
OT networks require unique cybersecurity protection because the devices located in these environments can have a lifespan of several decades and can be widely distributed across physical sites or plants. They also commonly use proprietary protocols which cannot be deciphered using traditional security tools, making it impossible to gain full visibility in the OT network.
The consequences of cyberattacks on IT vs OT also vary greatly. Cyber incidents impacting IT environments for example may result in reputational damage, theft, financial losses, or fines. While attacks to OT environments can result in more dire consequences that have the potential to impact health and human safety. To protect against new and existing cyber threats, OT environments require a unique approach to asset visibility, followed by the implementation of the proper steps to ensure effective and ongoing OT network monitoring.
Importance of Asset Visibility
Effective OT network monitoring starts with gaining a comprehensive, detailed, and up-to-date inventory of each asset in your OT network. However, OT environments are largely incompatible with the traditional IT solutions. As such, critical infrastructure organizations require multiple discovery methods in order to both identify all assets within the operational network, including those that use unique or proprietary protocols, are air-gapped, or are otherwise unreachable through passive-only means. Once full-spectrum visibility is established, organizations can consider other OT network protection tactics, like network segmentation.
Implementation of Network Segmentation
The implementation of OT network segmentation allows organizations to achieve enhanced security and improve overall network management. This process is particularly important in OT environments due to the critical infrastructure and essential devices that are used to control and monitor physical processes. With proper OT network segmentation, organizations can prevent the spread of cyberattacks by restricting their lateral movement through the network. By separating networks into smaller subsets, they become more manageable, and allow organizations to allocate their resources more efficiently by reducing traffic and improving network performance. Network segmentation is also critical in enabling organizations to meet the technical requirements of specific industry regulations.
Compliance with Industry Regulations
Many critical industries including oil and gas, transportation, food and beverage, manufacturing, and more, have very specific regulatory requirements for securing OT networks — such as NERC CIP, IEC 62443, or ISO 27001. However, monitoring and ensuring compliance with these regulations requires granular, properly tuned policies that many organizations lack. With the proper network segmentation strategy tailored to fit your organization's unique needs, you can meet technical requirements, implement the appropriate security controls and isolate critical assets.
Enhancing OT Network Monitoring
Alongside gaining asset visibility and implementing networking segmentation, there are several models and frameworks that can help your organization to enhance its OT network monitoring. These include:
Implementing the Purdue Model
The Purdue Model offers a comprehensive framework specifically designed for industrial control systems (ICS). Its multilayered structure helps to categorize the various components of ICS. This division is based on functionalities and offers five levels, each serving a distinct purpose.
Having segmented these networks into separate logical tiers, the Purdue Model serves as a cornerstone for developing secure and structurally refined industrial control networks. The model also enhances OT networking monitoring by facilitating improved network traffic analysis, allowing for rapid identification of abnormalities at any level and making it simpler to track. Additionally, it allows for more efficient resource allocation, ensuring critical systems receive the necessary resources, and the model supports enhanced governance and compliance by aligning with industry-specific standards. Overall, the Purdue Model paves the way for robust, efficient OT network monitoring.
Following the NIST Cybersecurity Framework
In addition to implementing the Purdue Model, organizations can follow a cybersecurity framework to help enhance both their OT network monitoring and manage their overall cybersecurity risks. Developed by the National Institute of Standards and Technology (NIST), their Cybersecurity Framework (CSF) provides organizations with voluntary guidelines, best practices, and standards for a flexible and risk-based approach to managing and improving their cybersecurity posture. NIST CSF is built around five core functions: Identify, Protect, Detect, Respond, and Recover. These functions, when implemented correctly, present a comprehensive approach to cybersecurity, ensuring not only a strong defense but also a resilient response mechanism.
Effective OT network monitoring hinges on an organization's ability to identify system components, implement adequate safeguards, promptly detect any anomalies, and respond and recover efficiently from cybersecurity events. By integrating this framework, you can tighten your grip on OT network monitoring — leading to improved security posture and resilience in the face of evolving cyber threats.
Safeguarding OT Networks with Claroty
At Claroty, we understand that there is no one-size-fits-all approach to OT network monitoring, that’s why on top of implementing the right cybersecurity models and frameworks we recommend partnering with a unified platform to help secure your mission-critical infrastructure.
Our platform employs multiple discovery methods to identify all assets within the operational network, including those that use unique or proprietary protocols, are air-gapped, or are otherwise unreachable through passive-only means. These capabilities enable us to provide the broadest, built-for-CPS solutions around Exposure Management, Network Protection, Secure Access, and Threat Detection — which allow for unprecedented OT network monitoring capabilities.
