Monitoring as OT cybersecurity strategy, with PRTG

• Asset protection: Safeguarding physical assets such as machinery, sensors, actuators, and control systems from cyber threats.
• Network security: Ensuring that the communication networks used in OT environments are secure from unauthorized access, eavesdropping, and tampering.
• System integrity: Maintaining the correct and intended operation of control systems, ensuring that data and commands are not altered maliciously.
• Availability: Ensuring that OT systems are available and operational when needed, as downtime can result in significant financial losses and safety hazards.
• Safety: Protecting the health and safety of personnel by preventing malicious actions that could cause physical harm.
• Compliance: Adhering to industry regulations and standards related to cybersecurity, such as NIST SP 800-82, IEC 62443, and NERC CIP.

A robust OT cybersecurity strategy is essential for several reasons, all of which contribute to the overall security, reliability, and efficiency of critical infrastructure and industrial operations. Here are the main reasons why having a strong OT cybersecurity strategy is a good idea:

• Protecting critical infrastructure, for example power grids, water treatment facilities, transportation systems
• Ensuring operational continuity by minimizing downtime and preventing cyber attacks
• Preventing financial losses by avoiding damage and implementing more cost efficiency
• Protecting intellectual property
• Meeting regulatory compliance and avoiding penalties
• Enhancing safety and protecting staff
• Adapting to technological convergence such as that of Information Technology and Operational Technology

Developing an effective cybersecurity strategy for OT environments requires a comprehensive approach that addresses the unique challenges and requirements of OT devices and systems.

Here are some aspects that should be considered:

• Asset inventory: Identify and document all OT assets, including hardware, software, networks, and communication protocols. This includes understanding the interdependencies between systems.
• Risk assessment: Conduct a thorough risk assessment to identify potential vulnerabilities, threats, and the impact of cyber incidents on OT systems. This should include evaluating both internal and external threats.
• Gap analysis: Compare current cybersecurity practices against industry standards and best practices to identify areas for improvement.
• Security policies: Establish comprehensive cybersecurity policies tailored to the OT environment. These should cover access control, data protection, incident response, and more.
• Compliance requirements: Ensure that policies and procedures comply with relevant regulations and industry standards (e.g., NERC CIP, IEC 62443, NIST SP 800-82).
• Access management: Implement robust access control measures, including role-based access control (RBAC), multi-factor authentication (MFA), and least privilege principles. Ensure that only authorized personnel have access to OT systems.
• Remote access security: Secure remote access to OT systems using VPNs, secure gateways, and strict authentication measures.
• Endpoint protection: Install and maintain endpoint protection solutions, such as antivirus software and host-based firewalls, on OT devices.
• Security Information and Event Management (SIEM): Use SIEM solutions to collect, analyze, and respond to security events in real time.
• Continuous monitoring: Implement continuous monitoring of OT networks and systems to detect and respond to security incidents promptly.
• Patch management: Implement a robust patch management process to ensure that all OT systems and devices are up-to-date with the latest security patches and updates.
• Vulnerability management: Conduct regular vulnerability scans and penetration testing to identify and mitigate vulnerabilities in OT systems.

In PRTG, “sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, for example the traffic of a switch port, the CPU load of a server, or the free space on a disk drive.

On average, you need about 5-10 sensors per device or one sensor per switch port.