Your Building is Online—Now What? Follow These Cybersecurity Measures to Protect Smart OT Infrastructure

Key Takeaways:

• IT/OT convergence creates new vulnerabilities.
• IoT devices are common entry points.
• Network segmentation is essential.
• Zero-trust architecture provides layered protection.
• Supply chain and ransomware risks are growing.

Imagine one minute your smart building could be fully optimized and humming along, then the next, chaos ensues as your HVAC system gets hacked through an unpatched IoT device. The result is stolen data, disruptions for occupants, and serious damage to your brand. It happens all the time. Fortunately, there are plenty of ways to prevent this from happening.

Modern smart building infrastructure encompasses a combination of IT and OT (operational technology) that serve distinct purposes, yet both require stringent cybersecurity measures. This includes IT systems such as PCs, laptops, tablets, smartphones, and servers, as well as OT, like intelligent HVAC, smart lighting, and access control systems. Interconnecting these is a wired and wireless network that typically comprises Ethernet, IP, BACnet, Wi-Fi, and private LTE.

As smart buildings become increasingly digitized and connected, it is essential to recognize that the blend of IT and OT introduces unique cybersecurity risks that must be mitigated. Let’s examine the various security challenges, threat vectors, the role of zero-trust architecture, and practical strategies to secure smart building assets and data.

Understanding OT Security Challenges as They Converge with IT

Security measures around operational technologies have lagged significantly behind IT. The reason for this is that OT, like HVAC systems, lighting, and elevator control platforms, are deployed and are in production for a decade or more. This leads to OT systems that vary widely in the type of protocols and networking technologies used. As these systems are refreshed, however, OT systems are transitioning to network transport standards like Ethernet, IP, and Wi-Fi, which are the norm in IT networks.

However, just because OT has converged with IT on the same network, securing OT devices often remains an afterthought, creating new gaps in the network that can easily be exploited. These potential gaps include:

• Unsecured IoT devices. Many OT devices, like sensors or controllers, lack built-in security features, using default credentials or unencrypted communications, making them easy entry points for attackers.
• Poorly integrated OT system security. OT systems are often not as securely protected as IT systems, with security patches delayed due to operational constraints or compatibility issues, leaving them susceptible to exploits.
• Inadequate network segmentation. Converged IT/OT networks may lack proper isolation, allowing attackers to move laterally from IT systems to critical OT infrastructure.
• Weak access controls. Insufficient authentication or authorization for OT devices enables unauthorized access, especially from compromised IT credentials or insider threats.

Breaches resulting from these security risks inherent to OT can lead to severe consequences, including the disabling of critical facility systems, environmental control failures, and the theft or loss of sensitive building and occupant data.

Decreasing the Risk of OT Threat Vectors

Because smart buildings rely on interconnected OT systems, implementing targeted strategies to mitigate these threat vectors is essential for securing smart infrastructure. Examples include:

• Securing IoT devices. Implement continuous authentication and authorization mechanisms to restrict who IoT devices are allowed to communicate with.
• Encrypt communications. Use secure transport protocols for OT systems to protect data in transit from interception or tampering.
• Vet supply chain partners. Implement strict vendor assessments and verify the integrity of software systems and patch updates to reduce risks from compromised third-party components.
• Deploy anti-ransomware measures. Use endpoint protection and schedule off-site OT system backups to limit the impact of ransomware attacks on critical infrastructure.

Implementing Zero-Trust for Smart Building OT

Zero-trust is a cybersecurity framework that assumes no user, device, or connection is inherently trusted, requiring continuous verification in order to access other secure systems on a network. In smart buildings where Operational Technology (OT) systems converge with IT systems and networks, zero-trust mitigates risks by enforcing strict access controls and continuous monitoring. Core components include identity verification (e.g., multi-factor authentication), least privilege access, and real-time network detection and response (NDR) for anomaly detection. This approach guarantees that even if one device is compromised, attackers cannot access other devices to infect them.

Securing Operational Technology (OT) through zero-trust requires authenticating all devices, including IoT sensors, using certificates or secure tokens to block unauthorized access. If this is not possible due to a lack of authentication mechanisms, network segmentation can be used to separate OT systems from IT infrastructure, thereby narrowing potential attack surfaces. Finally, continuous monitoring using AI-driven tools found in NDR platforms helps to identify unusual activities, such as unexpected commands sent to a building management system or data being sent to overseas locations.

A Secure Path Forward

Securing smart building OT infrastructure requires a proactive and flexible approach to address the unique cybersecurity challenges posed by the convergence of IT and OT systems. By mitigating threat vectors through secure IoT devices, encrypted communications, vetted supply chains, and anti-ransomware measures, organizations can protect critical operations. Implementing zero-trust architecture further strengthens defenses by enforcing strict access controls and continuous monitoring.

Next Steps for Building Owners and Tech Integrators:

1. Conduct an audit of all OT and IoT devices. Identify all connected OT assets in your building, including sensors, controllers, and BMS platforms and then replace any default credentials and ensure your firmware is updated regularly.
2. Implement zero-trust frameworks. If you haven’t already, start by integrating zero-trust protocols across IT and OT networks. Use certificate-based device authentication and role-based access control to minimize your exposure.
3. Segment your network. Have your IT team create separate VLANs for IT and OT systems, as this prevents lateral movement by isolating smart building systems from user-facing devices and external access points.
4. Encrypt all communications. Be sure to enforce use of secure protocols (e.g., TLS, HTTPS, VPNs) for all device-to-server and inter-device communications across your building’s infrastructure.
5. Vet and monitor vendors. Make it a requirement for third-party vendors to provide signed patch documentation, secure update pipelines, and compliance with cybersecurity standards (e.g., NIST CSF, ISO 27001).
6. Invest in NDR and AI monitoring tools. Deploy network detection and response platforms that leverage AI to flag unusual behavior—such as data exfiltration or unauthorized command execution—in real time.
7. Develop a cyber incident response plan. Work with your IT and OT departments and host tabletop sessions to review your response to a cyberattack. Take the time to establish clear protocols for dealing with potential breaches, including rapid containment, forensic investigation, stakeholder notification, and recovery timelines.