CYE Insights

10 Best Practices for Operational Technology (OT) Security

January 17, 2024

10 Best Practices for Operational Technology (OT) Security

As the integration of digital technologies in industrial processes continues to advance, the need for robust cybersecurity measures in Operational Technology (OT) environments becomes paramount. OT systems control and monitor physical devices and processes and are vital to businesses, regardless of whether they are part of manufacturing facilities, CNC machines, or critical infrastructure like airports, banks, and utilities.

The standard cybersecurity advice for IT and security managers of companies with OT networks is to make efforts to separate them from the regular networks. That being said, CISOs often talk about the separation of networks and the basic fundamentals that go with it, but they don’t make sure that these fundamentals are implemented well or consider the possible ramifications.

Recently, for example, we spoke to a client that asked for advice about different cybersecurity matters. Although the client had acceptable security, they were completely unaware that the OT network was connected by the IT staff to one of the administrative networks and basic security practices were not in place, thus potentially opening it to the outside world.

Here are ten best practices for securing operational technology (OT) cyber environments.

1.    Risk Assessment and Asset Inventory

The first step in OT cybersecurity is understanding the landscape. Conducting a thorough risk assessment and creating an exhaustive inventory of assets is crucial. This enables organizations to identify vulnerabilities, prioritize critical systems, and allocate resources effectively. Regular updates to this inventory should be made to account for changes in the environment.

2.    Access Control and Authentication

Implementing strict access controls and robust authentication mechanisms is essential. Each user should have the least privilege necessary to perform their job functions. This minimizes the potential damage an attacker can inflict if they gain unauthorized access. Recommended practices include multi-factor authentication, strong passwords, and biometric verification.

3.    Network Segmentation

Segmenting the network into isolated zones helps contain breaches and limit lateral movement by malicious actors. Critical systems should be isolated from less sensitive ones, and firewalls should be employed to regulate traffic between zones. This way, if one segment is compromised, the rest of the network remains secure.

4.    Patch Management and Vulnerability Assessment

Keeping software and firmware up-to-date is imperative for OT environments. Regularly scheduled patch management routines and vulnerability assessments should be conducted to identify and rectify weaknesses in the system. Additionally, a thorough testing process should precede any updates to ensure they don’t inadvertently disrupt critical operations.

5.    Remote assistance and maintenance

Remote assistance and maintenance should be performed with a fresh PC booted with a preassigned flash drive every time and a remote-control system that would need an approval for every connection.

6.    Intrusion Detection and Prevention Systems (IDPS)

Deploying IDPS tools helps with real-time monitoring of network traffic and events. These systems can detect suspicious activities and, in some cases, take automated actions to mitigate threats. Regularly reviewing and fine-tuning IDPS configurations ensures they remain effective against evolving attack vectors.

7.    Security Information and Event Management (SIEM)

SIEM solutions aggregate and analyze security data from various sources, providing a comprehensive view of the network’s security posture. This facilitates rapid incident response and enables organizations to identify trends or patterns indicative of potential threats.

8.    Employee Training and Awareness

Human error remains a significant factor in cyber incidents. Properly training employees on cybersecurity best practices and creating a culture of security awareness is crucial. This includes regular training sessions, simulated phishing exercises, and clear reporting protocols for suspicious activities.

9.    Incident Response and Business Continuity Planning

Having a well-defined incident response plan in place is essential. This plan should outline the steps to take in the event of a security incident, including roles and responsibilities, communication procedures, and containment strategies. Additionally, a robust business continuity plan ensures that critical operations can continue even during a cyber-attack.

10.  Regulatory Compliance and Standards

Adhering to industry-specific regulations and cybersecurity standards is essential for OT environments. Compliance with frameworks like NIST, IEC 62443, and ISO 27001 demonstrates a commitment to security and can provide a structured approach to implementing best practices.


Securing OT cyber environments is of paramount importance in today’s interconnected industrial landscape. By following these best practices, organizations can mitigate risks, enhance operational resilience, and safeguard critical infrastructure. Implementing a holistic approach to cybersecurity not only protects assets and data, but also ensures the safety of employees and the continuity of operations in the face of evolving cyber threats.

Want to learn more about how to secure OT cyber environments? Contact us. 

Elad Leon

By Elad Leon

Elad Leon is Senior CTI Expert at CYE. He is a reserve major in the Israel Defense Forces and has more than a decade's experience working in the defense and intelligence community. He specializes in strategic analysis, operations management, and threat actor engagement.