It is well known that OT networks are fundamental in the industrial sector and require a series of characteristics to maintain their operability and control over the various physical processes that may occur within them. These characteristics include their presumed high availability and reliability, real-time communication and quick response, the need for a solid foundation in cybersecurity, and their integration with specialized devices such as PLCs and SCADA systems.
Effective monitoring of our OT networks not only allows us to meet these requirements and comply with current regulations but also helps protect industrial systems and the data they contain from threats, thus ensuring operational continuity and process efficiency.
Objectives of Best Practices
- Physical Security: Implementing best monitoring practices focused on maintaining OT network security helps protect its physical processes and infrastructure, preventing attacks that could cause damage to its elements and pose human risks.
- Availability and Operational Continuity: Maintaining the best monitoring practices minimizes the risk of interruptions and production losses.
- Compliance with Standards and Regulations: Best monitoring practices bring networks closer to security standards and regulations.
- Protection of Sensitive Data: OT networks commonly handle critical information. Best practices ensure that we protect this data against unauthorized access.
- Threat Recovery Capability: Best practices allow organizations to adapt and respond effectively to current threats, facilitating action protocols in case they are affected.
- Robustness and Trust: The ability to maintain secure operations ensures peace of mind for administrators and strengthens the trust of customers, partners, and regulators in the organization.
Best Practices for OT Networks
- Identification of Critical Points: A comprehensive vulnerability analysis can help us find and protect the main attack points of our network, especially if they are critical assets. It is recommended to start with Industrial Control Systems (ICS), such as PLCs and SCADA systems. Additionally, we will pay special attention to those network devices that connect our OT systems, such as routers, switches, and firewalls.
- Implementation of Monitoring Tools: Using tools and automated processes can provide a global view of our network. We recommend that these tools provide real-time visibility of network traffic and information on security events, such as notifications or alerts. Additionally, it is important to segment the network to improve its management and limit what the attackers can reach.
- Use of Intrusion Detection Systems (IDS): These systems can be signature-based or anomaly-based. They identify and compare anomalies with a signature database, while the latter focus on detecting unusual behaviours that may indicate a threat.
- Access Management: Limiting access to system assets prevents unauthorized access and allows us to narrow down the number of responsible parties for better internal organization. Strict access controls should be enforced, with multi-factor authentication and strong passwords to protect critical systems.
- Cybersecurity Updates: It is crucial to keep all systems and devices updated with the latest security patches, both on a timely and scheduled basis.
- Training: Employees should be trained in cybersecurity practices and know how to respond to incidents. This can be achieved through courses and specific training sessions, updated to the current needs of our systems.
Common mistakes
- Network Overload: We recommend not installing too many sensors and monitoring devices that could affect performance. Ideally, we should only place the necessary number to cover the network’s most critical attack points.
- Ignoring Security Alerts: False positives are common when relying on an alert system. Even if they are false, we should not ignore security alerts.
- Not Segmentation of the Network: An attack on an unsegmented network will spread more quickly.
- Insufficient Cybersecurity Integration: Failing to consider the cybersecurity of an OT system from its design and implementation can create easily exploitable gaps.
- Obsolete systems: Not regularly applying security patches and updates, delaying their application, or using outdated devices makes systems vulnerable to perfectly avoidable current known attacks.
- Insecure Internet Access: Connecting OT systems to networks without adequate security measures should be avoided, as it increases the attack surface and exposes our systems to external threats.
Guardian and Monitoring in OT Networks
We strive to create an advanced solution for monitoring and safeguarding OT networks with Guardian. Below are our key design considerations as a practical example:
- Complete Visibility: Guardian aims to provide comprehensive visibility of network traffic and security events in real time. It ensures the early detection of threats and anomalies.
- Network Segmentation: Guardian facilitates the segmentation of the OT network. It helps limit the scope of potential attacks and improve security management without being cumbersome for administrators.
- Anomaly Detection: Guardian integrates an intrusion detection system (IDS) based on signatures and machine learning algorithms that analyse traffic behaviour, statistics, and operational process variables (UEBA, User Entity Behaviour Analytics) to identify suspicious behaviours, known or unknown threats and even physical safety issues for employees or customers.
- Security Updates: It helps keep all systems and devices updated with the latest security patches, reducing vulnerabilities.
- Training: Our company includes training modules to ensure the employees are prepared to respond to security incidents.
Conclusions
Implementing best monitoring practices in OT networks is essential to ensure the security, availability, and efficiency of industrial systems. Solutions like the ones we offer with Guardian provide the necessary tools to protect physical processes, infrastructure, and sensitive information, minimizing the risks of disruptions and cyberattacks.
By following these practices, organizations can comply with security regulations, improve their resilience to threats, and strengthen the trust of customers, partners, and regulators.