Best Practices for Cybersecurity in Predictive Maintenance

Predictive maintenance relies on IoT sensors, AI, and connected systems to prevent equipment failures. But with increased connectivity comes higher cybersecurity risks. Attacks on predictive maintenance systems can cause physical destruction, production downtime, and financial losses. In 2025 alone, manufacturing accounted for 42% of operational technology (OT) threats, with ransomware attacks rising by 64%.

Here’s what you need to know:

• Key Threats: Data poisoning, ransomware, and breaches at IT/OT boundaries.
• Major Risks: Equipment damage, safety hazards, and operational downtime costing up to $260,000 per hour.
• Essential Defenses: Security audits, patch management, access controls, encryption, and employee training.

Actionable Steps:

1. Conduct regular security audits using safe, OT-specific tools.
2. Implement centralized, automated patch management systems.
3. Strengthen access controls with multi-factor authentication and network segmentation.
4. Encrypt all data in transit and at rest, and secure mobile devices.
5. Train field teams on cyber threats and develop robust incident response plans.

Investing 5–10% of your maintenance budget into cybersecurity can prevent catastrophic losses, protect workers, and ensure uninterrupted operations. Don’t wait - start securing your systems today.

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Predictive Maintenance and Cybersecurity

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Conducting Regular Security Audits and Assessments

The first step in protecting predictive maintenance systems from cyber threats is understanding what you're protecting and identifying potential weak spots. Regular security audits are crucial for this, but testing operational technology (OT) systems requires extra care to avoid unintended consequences like crashing PLCs or triggering shutdowns. In fact, 73% of OT assessments encounter incidents due to poorly scoped tests and inadequate preparation.

Before starting an audit, it's essential to define clear boundaries. Identify the plants, production lines, and assets (like PLCs, HMIs, and sensors) that need evaluation. Plan ahead by scheduling blackout windows and emergency stops to minimize disruption. A detailed asset inventory is especially critical for OT environments, where legacy systems often have limited fault tolerance and undocumented "shadow IT" connections that attackers can exploit.

Once these preparations are in place, automated scanning and simulation-based testing can help manage risks more effectively.

Automated Vulnerability Scanning

With boundaries in place, automated tools can safely monitor network traffic without causing disruptions. These tools analyze maintenance data streams in real time, identifying potential security incidents before they escalate. This proactive approach can reduce forensic investigation timelines from weeks to just hours by providing detailed activity logs and attack reconstructions. For OT environments, choose protocol-aware tools that understand industrial protocols like Modbus, DNP3, OPC, and BACnet.

Using default IT scanners like Nmap in OT environments can be risky - they can overload network stacks and crash critical systems like PLCs and HMIs. Instead, rely on passive reconnaissance methods, such as monitoring traffic through taps or span ports, to maintain system stability while detecting vulnerabilities. Behavioral analytics can also establish baseline patterns to spot anomalies, such as unexpected data transfers or unauthorized access during off-hours.

Penetration Testing and Risk Prioritization

After audits, penetration testing helps confirm which vulnerabilities require immediate action. Not all vulnerabilities are equal - prioritize them based on their impact on safety, production, exploitation likelihood, and the complexity of remediation. In OT environments, the biggest risks are production downtime, equipment damage, and threats to human safety, rather than traditional concerns like data loss. For example, a "Critical" vulnerability behind multiple firewalls might pose less risk than a "Medium" vulnerability on an internet-facing HMI.

Simulation-based testing using digital twins offers a safer way to validate security measures without disrupting live production. This method can uncover far more attack paths - up to 10 times more - compared to manual testing. Plus, it’s faster and more cost-effective. While manual testing can take 3-5 months per site and cover only 5-8% of the attack surface, simulation-based assessments can achieve 100% coverage in just 1-2 weeks at significantly lower costs.

When prioritizing risks, consider four key factors:

• Safety implications: Could the vulnerability lead to physical harm?
• Production impact: Downtime can cost over $30,000 per minute in heavy manufacturing.
• Likelihood of exploitation: Is the vulnerability easily accessible via the network?
• Remediation complexity: Can the issue be patched without risking system stability?

For legacy systems that can't be easily patched, alternative measures like network segmentation may be necessary to maintain security without compromising operational stability.

Implementing Effective Patch Management Strategies

Once you've identified vulnerabilities, the next step is updating your systems without disrupting their operation. This is especially critical given the staggering pace of new threats - the National Vulnerability Database reports over 350 new vulnerabilities weekly. In 2021 alone, 80% of OT/ICS organizations faced ransomware attacks. Delaying updates leaves systems wide open to exploitation, particularly in OT environments where systems often run 24/7 and rely on legacy hardware that can be over a decade old. In these cases, patching requires meticulous planning to avoid disrupting essential equipment.

The key challenge? Balancing security needs with operational stability. Unlike IT systems, which can typically be rebooted quickly, industrial control systems often lack dedicated testing environments. That means every patch deployment carries some risk. As Robert Valkama, Senior Manager of OT Cybersecurity at Fortum, advises:

"The biggest mistake you can make is to panic and try to do everything at the same time. Doing everything as soon as possible can be valid in IT, but it might not lead to the best results in OT."

To tackle this, an organized and automated approach is necessary to ensure updates are applied securely and with minimal disruption.

Centralized and Automated Updates

Manually managing patches across multiple sites is both inefficient and prone to errors. A centralized system can streamline the process by automating vulnerability identification and patch deployment. Start by creating a detailed asset inventory that tracks every piece of software, firmware, and hardware - from the industrial demilitarized zone down to individual sensors and PLCs. Use automated tools to keep this inventory up to date, as you can’t patch what you don’t know exists. As Ari Rajamäki, Product Manager for Cybersecurity at Valmet, explains:

"You need to know what you have to be able to develop."

Once the inventory is in place, automated tools can compare it against sources like the National Vulnerability Database and ICS-CERT advisories. This helps identify which patches are relevant to your specific assets. Assign criticality scores to vulnerabilities by considering factors like safety risks, potential profitability impacts, and recovery metrics such as Recovery Time Objective (RTO) and Recovery Point Objective (RPO). For example, a vulnerability in a safety-critical system with a short RTO should take precedence, even if its CVSS score isn’t the highest.

From there, use a central console to deploy patches programmatically across devices. Start with low-risk assets and ensure rollback features are enabled in case a patch causes issues. This phased approach allows you to test updates in real-world conditions without jeopardizing your most critical systems. For legacy equipment that can’t be patched, consider interim measures like virtual patching or network segmentation until proper maintenance can be scheduled.

Scheduling Updates During Low-Impact Periods

When it comes to patching OT systems, timing is everything. Schedule updates during low-risk production periods to minimize disruption. Coordinate with operational teams to align updates with planned shutdowns or off-peak hours. For example, avoid patching pipeline control systems during peak demand or production lines during critical runs. In particularly cautious environments, an "N minus 1" strategy can be used to avoid unforeseen bugs.

Before rolling out any patch, test your backups and establish a formal rollback plan. Even fully approved patches can sometimes cause system crashes. Connect your patch management system to your Computerized Maintenance Management System (CMMS) to automate work order generation and confirm the availability of spare parts before starting a patch cycle. This ensures your team is ready to restore operations quickly if something goes wrong.

Another way to simplify patch management is by reducing your attack surface. Remove outdated software like Adobe Flash or unused document readers from OT servers. This not only improves security but also reduces the number of patches you need to handle, allowing you to focus on protecting the systems that matter most.

Strengthening Access Controls and Network Security

Beyond secure patch management, tightening network access controls is critical to blocking unauthorized access and limiting lateral movement. Safeguarding devices alone won’t cut it - network segmentation and strict access controls are just as important. In fact, 65% of OT breaches in 2025 are expected to stem from weak network segmentation at the IT and OT boundaries. When maintenance systems are linked to corporate networks or cloud platforms, they can unintentionally create direct pathways for attackers to access critical infrastructure. The stakes are high - $28 million is the estimated average cost of a single OT/ICS breach, factoring in operational downtime and recovery.

Predictive maintenance, which relies on constant data exchange across network zones, poses unique challenges. Without clear boundaries and strict access controls, something as simple as a compromised maintenance tablet or vendor login could open the door to attackers. This is why protecting predictive maintenance environments - like sensor networks, edge gateways, and CMMS platforms - is essential. These efforts work hand in hand with security audits and patch management to maintain operational safety. As cybersecurity expert Johnson puts it:

"An unsecured CMMS is a direct window into your operational environment."

Here’s how you can enforce strong identity verification and create effective network segmentation.

Multi-Factor Authentication and Role-Based Access Control

Every device and user should authenticate before accessing predictive maintenance systems. Start by assigning unique identities to IIoT devices using X.509 certificates, security tokens, or other cryptographic methods. For devices that support it, deploy Trusted Platform Modules (TPMs) or similar hardware-protected modules to secure credentials even in cases of physical compromise.

For maintenance personnel, adopt Multi-Factor Authentication (MFA) and implement Role-Based Access Control (RBAC). This ensures technicians only access data and systems directly relevant to their tasks. For example, a field technician working on a single pump shouldn’t have access to the entire plant’s control systems. By applying the principle of least privilege, you limit permissions to the bare minimum needed for each user, device, or application.

Avoid storing credentials or secrets locally on OT and IIoT devices, as this creates vulnerabilities. Instead, use automated systems for credential generation, rotation, and revocation. For third-party vendors, enforce "time-boxed" access, which ensures their permissions expire automatically when their work is completed, reducing the risk of stale credentials.

Network Segmentation and Zero-Trust Principles

Strong authentication is a good start, but isolating network segments is key to stopping lateral movement. Maintenance systems should run on isolated network segments, separate from corporate IT systems and the public internet. The Purdue Model is a helpful framework for defining network zones, including demilitarized zones (DMZs) to manage traffic between industrial and corporate networks. Safety networks should also be physically or logically separated from business and control networks to ensure breaches don’t interfere with critical safety functions.

Microsegmentation takes this a step further, creating smaller zones around individual assets based on their importance. This limits an attacker’s ability to move through your network after a breach. Use OT-aware IDS tools that understand industrial protocols like Modbus, DNP3, and IEC 61850 to detect unusual activity, as traditional IT tools often fall short in this area.

For older assets that lack modern authentication capabilities, protocol converters can help by translating insecure industrial protocols into secure ones close to the device. When sending sensor data to cloud-based predictive analytics platforms, consider unidirectional gateways or data diodes. These ensure data flows out for analysis but prevent attackers from using the same path to infiltrate your systems.

Zero-trust architectures operate on the principle of "never trust, always verify." Every maintenance session, vendor login, and CMMS integration must verify its security posture before accessing resources. Treat your CMMS as a critical security checkpoint - ensure all integrations with historian servers or DCS portals use encrypted tokens and frequently rotated credentials. As the Claroty Team highlights:

"The principle of 'never trust, always verify' is nothing short of essential when it comes to protecting critical infrastructure, and it's the core tenet of zero trust architectures that enable segmentation." - Claroty Team

Protecting Data and Devices in Predictive Maintenance

While strong access controls and network segmentation are essential, they’re just the starting point. The data itself - and the devices technicians rely on - require additional protection. Industrial facilities have seen cyberattacks soar by over 2,000% in recent years, with maintenance systems becoming a prime target. These systems store critical details like equipment specs, failure patterns, production schedules, and proprietary algorithms - making them highly attractive to hackers. Without proper encryption and endpoint security, something as simple as a stolen tablet or intercepted sensor data could jeopardize your entire operation.

Encrypting Data In-Transit and At-Rest

To safeguard maintenance data, encryption is non-negotiable. Ensure all data - from sensors to analytics platforms - is encrypted. Use TLS 1.3 for web-based systems, steering clear of outdated SSL/TLS versions with known vulnerabilities. For technicians accessing networks via public Wi-Fi, deploy VPNs using modern protocols like WireGuard or IPsec. When transmitting sensor data to cloud-based analytics platforms, implement end-to-end encryption to block unauthorized access along the way.

For data stored on devices, AES-256 remains the gold standard. Enable Full Disk Encryption (FDE) on laptops and tablets using tools like BitLocker or FileVault to protect against theft or loss. In environments with limited resources, such as IoT sensors, Elliptic Curve Cryptography (ECC) offers strong security with smaller key sizes. For instance, a 256-bit ECC key matches the protection of a 3,072-bit RSA key, making it ideal for battery-powered devices.

Store encryption keys securely, using Hardware Security Modules (HSMs) or cloud-based Key Management Systems (KMS). Never embed keys in software or firmware; instead, use secure vaults or environment variables. Remember, more than 70% of encryption vulnerabilities arise from flawed implementation rather than weak algorithms. As Christopher Porter from Training Camp explains:

"The strength of modern encryption lies not just in the algorithms themselves, but in their proper implementation."

For older equipment lacking native encryption, use security gateways or encrypted tunnels to protect outgoing data. Automate key rotation regularly and replace compromised keys immediately to maintain security.

Once encryption is in place, the next step is securing the devices technicians use every day.

Securing Mobile Devices and Endpoints

Technicians often use tablets, laptops, and diagnostic tools that connect directly to maintenance systems. Unfortunately, a single compromised device can serve as an entry point for attackers. To mitigate this risk, harden devices by enabling secure boot, encrypted storage, and mandatory session timeouts. Change all default credentials immediately - these are often publicly available and easily exploited.

Integrate device access with enterprise identity providers like Azure AD or Okta, and enforce multi-factor authentication (MFA) to reduce the risk of stolen credentials. Behavioral analytics can help by identifying unusual patterns, such as access during off-hours or unexpected data transfers. If a breach is suspected, disconnect the device from the network immediately to prevent further damage.

For third-party contractors, issue time-limited credentials tied to specific work orders. These credentials should automatically expire once the job is completed, limiting exposure. Allocate 5–10% of your maintenance technology budget to cybersecurity - this proactive step can save millions by preventing breaches.

Regular Backups and Recovery Testing

Even the best defenses can’t guarantee total protection, which is why reliable data recovery is critical. Maintenance data is a frequent ransomware target, with attackers increasingly focusing on online backups. Maintain offline backups of critical data and system configurations, and regularly test recovery procedures to ensure minimal downtime in the event of an attack.

The financial stakes are high. The median cost of a ransomware attack in manufacturing is $600,000, and the average dwell time in operational technology (OT) environments before detection is 42 days. Predictive maintenance can reduce unplanned equipment failures by 55%, but those gains disappear if a cyberattack takes systems offline.

To streamline recovery efforts, classify your maintenance data. For example, mark failure patterns as "Highly Confidential" while designating manuals as "Public." This approach ensures appropriate encryption levels and helps prioritize restoration in a crisis.

Building a Cybersecurity Culture in Field Service Teams

Relying on technology alone won't secure predictive maintenance systems. A cybersecurity-first mindset among field service teams is crucial to ward off attacks that could disrupt operations or damage equipment. Human error accounts for 74% of security breaches, with each incident costing organizations an average of $4.88 million. Field technicians - those using tablets, connecting to SCADA systems, and handling sensitive equipment data - are both a potential risk and a key line of defense.

Employee Training on Cyber Threats

Technical controls alone aren't enough; training employees to recognize and respond to cyber threats is just as important. Annual training sessions often fall short for field technicians who face unique challenges. Instead, use targeted, short-form micro-learning modules - each under eight minutes - focused on real-world scenarios. These could include compromised devices, unauthorized SCADA access, or phishing attempts disguised as vendor emails.

Start with phishing simulations to identify gaps in knowledge, then create training tailored to maintenance workflows rather than generic office scenarios. AI-driven platforms that provide just-in-time coaching can boost engagement with security training by up to 40%. Embed this training into your Computerized Maintenance Management System (CMMS) so technicians receive relevant security tips when taking on high-risk tasks, like servicing IoT sensors or variable frequency drives.

For hands-on tasks, consider the "Shadow-Reverse" approach: shadow an expert, debrief afterward, and then perform the task under supervision. Make it easy for employees to report potential threats by offering one-click "Report Phish" buttons, and recognize those who identify real attacks with digital badges or public acknowledgment. Teach immediate response steps like disconnecting compromised devices, notifying IT, and documenting suspicious activity with screenshots instead of forwarding harmful emails. Replace annual training sessions with quarterly micro-refreshers to keep security top-of-mind. These efforts work hand-in-hand with automated defenses and strict access controls.

Developing Incident Response Plans

Even the best technical defenses need to be backed by well-thought-out incident response plans. These plans should bridge the gap between IT security and operational technology (OT) teams. Unlike traditional IT breaches, where there’s more time to react, a compromised programmable logic controller (PLC) can cause equipment damage in seconds. Incident protocols must ensure rapid, coordinated responses.

Integrate your plan with Security Information and Event Management (SIEM) systems to monitor maintenance data streams in real time, flagging unusual activity like unauthorized access or unexpected data transfers. Automate high-priority CMMS work orders when threats are detected, immediately alerting technicians to check for physical damage caused by digital interference. Use dynamic micro-segmentation to isolate compromised systems without halting production, maintaining uptime while containing the threat.

Run joint tabletop exercises to clarify roles and uncover communication gaps before an actual incident occurs. Include features like vendor credentials that expire automatically after work orders close, preventing attackers from lingering in your systems. Use CMMS forensic audit trails - such as timestamped user IDs and vendor access logs - to trace how breaches occurred and assess their scope.

As Tim Cheung, CTO and Co-Founder of Factory AI, puts it:

"Is my security system smart enough to know the difference between a broken bearing and a breached firewall?"

Incorporate sanity checks based on physics: if sensor data doesn’t align with expected control data, trigger an immediate investigation. Dedicate 5–10% of your maintenance technology budget to cybersecurity measures, including incident response planning. This modest investment can save millions by preventing breaches and avoiding costly downtime.

Conclusion

A strong cybersecurity strategy in predictive maintenance isn't just a precaution - it's a necessity for uninterrupted operations. The numbers tell the story: in 2025, manufacturing was a major target for OT threats, with ransomware attacks on industrial systems jumping by 64% from the previous year. The cost of operational downtime is staggering, averaging $260,000 per hour, and a single OT breach in the energy sector can rack up losses of $28 million.

The strategies covered in this article - like network segmentation, multi-factor authentication, encrypted data, and employee training - are critical for safeguarding the IT/OT boundary, where 75% of attacks occur. These practices can dramatically reduce ransomware detection times from 42 days to just hours and prevent attackers from moving between corporate networks and production control systems.

As Johnson, an industrial security expert, put it:

"The plants that secure their CMMS today will not be the breach headlines of 2027."

Investing 5–10% of your maintenance technology budget in cybersecurity isn't just a cost - it's a shield against devastating losses. Consider Jaguar Land Rover's $255 million hit in late 2025, when a five-week breach shut down three assembly lines. That kind of disruption is avoidable.

Proactive security measures not only protect your predictive maintenance ROI - which often delivers 25–30% cost savings and extends asset life by 20–25% - but also safeguard workers, prevent equipment damage, and ensure critical systems are always available. When the stakes are this high, the real question isn't whether you should act - it's whether you can afford not to. Taking action today ensures safer, uninterrupted production for the future.

FAQs

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How can I audit OT systems without causing downtime?

To keep operations running smoothly during OT audits, schedule them during maintenance windows when systems are already offline. This timing reduces the risk of interruptions. Opt for non-intrusive techniques, such as network segmentation, controlled access, and continuous monitoring, to pinpoint vulnerabilities without interfering with day-to-day operations. You can also leverage AI-driven tools to spot anomalies in real-time. These tools help maintain system availability by reducing the reliance on invasive testing methods. :::

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What’s the safest way to patch legacy PLCs and HMIs?

Virtual patching is the most reliable approach to securing legacy PLCs and HMIs. Instead of modifying the actual software or firmware, this method establishes security policies and rules within the network path. By doing so, it protects against vulnerabilities while minimizing the risk of system interruptions. :::

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How do I secure the IT/OT boundary in predictive maintenance?

To safeguard the IT/OT boundary in predictive maintenance, it’s crucial to implement a cohesive cybersecurity approach that provides real-time visibility across both domains. Here’s how you can strengthen your defenses:

• AI-driven monitoring: Use advanced AI tools to spot anomalies and potential threats as they emerge. Early detection is key to avoiding disruptions.
• Ongoing system monitoring: Keep an eye on ICS, PLCs, and other connected systems to ensure no unauthorized access slips through the cracks.
• Layered security measures: Deploy firewalls and enforce strict access controls to protect your operations while maintaining smooth workflows.

By combining these practices, you can enhance security without compromising operational efficiency. :::