Category: Operational Technology

Operational Technology (OT) environments are the backbone of industrial systems, encompassing everything from manufacturing plants to energy grids. Monitoring these environments is critical for maintaining security, reliability, and operational efficiency. Two common approaches for network monitoring in OT environments are active monitoring and passive monitoring. Both methods have their merits and challenges, and selecting the right approach often depends on the specific needs and constraints of the environment.

Active Network Monitoring

Active network monitoring involves sending probes or test packets into the network to assess its performance, availability, and security. This approach is often used to simulate network behavior and detect anomalies.

Pros of Active Monitoring:

• Real-Time Insights: Active monitoring provides immediate feedback on network performance and potential issues.
• Detailed Diagnostics: Enables granular troubleshooting by actively querying devices and systems.
• Proactive Issue Detection: Can simulate attack scenarios or performance bottlenecks to identify vulnerabilities before they become critical.

Cons of Active Monitoring:

• Network Disruption Risks: Injecting additional traffic may cause latency or interfere with time-sensitive OT processes.
• Complex Deployment: Requires careful configuration to avoid unintended consequences in sensitive OT systems.
• Limited Scalability: Active monitoring can become resource-intensive in large-scale environments.

Risks Associated with Active Monitoring:

• Operational Impact: Poorly designed monitoring could inadvertently disrupt industrial processes.
• Security Risks: Malicious actors could exploit active monitoring tools or traffic as an attack vector.
• Compliance Challenges: Some industries have strict guidelines on allowable network traffic within OT environments.

Passive Network Monitoring

Passive monitoring involves capturing and analyzing existing network traffic without injecting any additional packets. This method is often favored for its non-intrusive nature.

Pros of Passive Monitoring:

• Non-Disruptive: By only observing existing traffic, passive monitoring minimizes the risk of interfering with critical OT operations.
• Broad Visibility: Provides a holistic view of network behavior over time.
• Scalability: Can be more easily scaled across large environments without adding additional load to the network.

Cons of Passive Monitoring:

• Limited Real-Time Insights: Since it relies on analyzing existing traffic, passive monitoring may not detect issues as they happen.
• Blind Spots: If certain network segments are idle or underutilized, they may not generate sufficient data for analysis.
• High Data Volume: Requires significant storage and processing capabilities to analyze captured traffic effectively.

Risks Associated with Passive Monitoring:

• Delayed Detection: Slow-moving or stealthy threats may go unnoticed until significant damage is done.
• Data Privacy Concerns: Capturing all traffic may expose sensitive information to unauthorized access.
• Complex Analysis: Requires advanced tools and expertise to interpret the captured data accurately.

Choosing the Right Approach

The choice between active and passive monitoring in OT environments depends on several factors, including:

1. Operational Sensitivity: Highly sensitive systems may favor passive monitoring to avoid disruptions. Read more about scanning in OT Environments in and article written by Zane Blomgren on Automation.com here.
2. Regulatory Compliance: Industry regulations may dictate which monitoring methods are permissible.
3. Threat Landscape: Active monitoring may be better suited for environments facing advanced persistent threats (APTs).
4. Resource Availability: Passive monitoring may be ideal for environments with limited bandwidth or processing capacity.
5. Use Case: Proactive threat hunting or troubleshooting may necessitate active monitoring, while long-term trend analysis is better suited to passive approaches.

Hybrid Monitoring: Combining the Best of Both Worlds

In many cases, a hybrid monitoring strategy that leverages both active and passive methods can provide a balanced approach. For example:

• Use passive monitoring for continuous traffic analysis and baseline creation.
• Deploy active monitoring during scheduled maintenance windows or for targeted diagnostics.

By combining these approaches, organizations can achieve a more comprehensive security posture while minimizing risks. Read more about how each approach has it’s place in a comprehensive cybersecurity approach in Patrick Gebhardt’s post on Cybersecurity for OT networks: navigating the digital landscape.

Conclusion

Active and passive network monitoring each have distinct advantages and drawbacks. When monitoring OT environments, understanding the trade-offs and potential risks associated with each method is crucial. By tailoring the approach to the specific needs of the environment and adopting a hybrid strategy when appropriate, organizations can enhance their ability to detect threats, ensure compliance, and maintain operational efficiency.

In a bold move that underscores the increasing importance of cybersecurity in the industrial sector, Rockwell Automation has issued a public advisory in response to heightened geopolitical tensions and adversarial cyber activities globally. This notice is not just a precaution; it’s a call to immediate action for all organizations utilizing Industrial Control Systems (ICS).

The Advisory: A Critical Step Forward

Rockwell’s advisory urges all customers to take immediate steps to assess whether they have devices connected to the public internet and, if so, to disconnect any that are not specifically designed for such exposure. This directive is a critical reminder of the vulnerabilities that can arise from internet-facing Operational Technology (OT) devices, which are often targeted by malicious actors seeking to exploit weaknesses in ICS environments

Why This Matters

The significance of Rockwell’s public stance cannot be overstated. As a leading player in the automation and control systems industry, Rockwell’s decision to issue this advisory sets a precedent that could influence other vendors to adopt similar measures. The interconnected nature of today’s industrial environments means that a breach in one system can have cascading effects, potentially impacting operations, safety, and the broader supply chain.

A Broader Implication for ICS Vendors

While Rockwell has taken the lead, this advisory serves as a wake-up call for all ICS vendors. The cybersecurity landscape is evolving rapidly, and the threats are becoming more sophisticated. Vendors must prioritize the security of their products and provide clear guidance to their customers on best practices for safeguarding their systems.

Steps to Take Now

For customers and vendors alike, the message is clear: act now. Here are a few steps to consider in light of Rockwell’s advisory:

1. Conduct a Thorough Assessment: Identify all devices within your network that are connected to the public internet. Assess whether these devices need to be publicly accessible and determine their security posture.
2. Disconnect Non Essential Devices: Immediately disconnect any devices that are not specifically designed for public internet connectivity. This step is crucial to reducing the attack surface and mitigating potential threats.
3. Implement Robust Security Measures: If a device has to be internt-facing ensure strong security measures are in place, including firewalls, intrusion detection systems, and regular security updates.
4. Educate and Train Staff: Cybersecurity is a collective responsibility. Ensure that all employees are aware of the risks associated with internet-facing devices and are trained on best practices for maintaining security.

Looking Ahead

Rockwell Automation’s advisory is a timely reminder of the critical importance of cybersecurity in today’s industrial landscape. As threats continue to evolve, it is imperative that all ICS vendors and their customers take proactive steps to safeguard their systems. By working together and prioritizing security, we can build more resilient industrial environments capable of withstanding the challenges of the modern threat landscape.

Conclusion

In conclusion, Rockwell’s public advisory is a commendable step that highlights the urgent need for action in the face of escalating cyber threats. It is a call to arms for the entire ICS community to reassess their security measures and ensure that they are prepared to defend against potential adversaries. Let’s take this opportunity to reinforce our defenses and protect the critical systems that underpin our industrial infrastructure.