Today’s industrial facilities are more connected than ever before. That’s mostly thanks to the massive opportunities and benefits that the Industrial Internet of Things (IIoT) brings.
These (often tiny) devices bring levels of productivity, efficiency, and insight that have never been available before. Sensors can track machine performance in real time, predict maintenance to avoid downtime, and connect supply chains to keep everything moving. Put simply, IIoT data means business leaders can make better quality decisions and outcomes.
But as with all digital innovations, this increased connectivity comes with potential for risk. And for many companies, there’s a lot on the line. We’ve seen examples of compromised IIoT bringing production to a halt, with knock-on effects to customers and reputations.
So, how can you make sure you secure your IIoT environment against common threats? To help protect your business, we’ve put together some practical steps you can take to build a strong, layered defence.
H2 - What is the security of industrial IoT (IIoT)?
The IIoT is a collective name for a huge network of connected devices in factories and other operational settings. These might include sensors for monitoring equipment, devices that detect wear and tear and even controllers that keep production lines moving. Combining existing operational technology (OT) with data, IIoT brings intelligence and automation into areas that were once managed manually or in isolation.
But, as we’ve seen, many of these IIoT devices were not designed with modern cyber security in mind. They can be vulnerable to a range of threats, such as denial-of-service (DoS) attacks, ransomware, data manipulation, or tampering. The problem is often made worse because many security tools built for broader IT systems are not a perfect fit for OT.
That requires a specialised approach. IIoT security flaws can lead to business-critical issues like defective products, delayed detection of issues, interrupted production, or even malware spreading into business networks or partner organisations. We therefore must safeguard all devices to protect the whole business.
The biggest risk in IIoT security is doing nothing. As manufacturing environments become more connected, the attack surface expands and so does the opportunity for threat actors. Ignoring the need for protection doesn’t preserve the status quo; it invites disruption. A single breach can halt production, compromise safety, and damage trust. Proactive investment in IIoT security isn’t just about defence, it’s about ensuring continuity, competitiveness, and confidence in a digital-first future.
What are the vulnerabilities of IoT in industry?
To implement IIoT security best practices, it’s important to understand what problems we might face… and why. Unlike traditional IT environments, IIoT networks control real-world operations using tools that were often not designed with modern threats in mind. Here are some of the potential issues IT teams face.
Our work with manufacturers highlights a critical truth in that IIoT security isn’t just about protecting data, it’s about safeguarding entire production ecosystems. From legacy equipment vulnerabilities and third-party access risks to the sheer scale of connected devices, the attack surface is vast and evolving.
Outdated equipment
Let’s face it, industrial and manufacturing settings don’t always have the latest and greatest tech. In fact, many operational systems still rely on decades-old hardware and software. These legacy systems were never designed to be connected to the internet, yet many are now online.
Without incredibly important protections like encryption, secure protocols, or patching capabilities, they become soft targets for potential attackers. Things like regular updates and careful planning are essential, though, of course, these need to be balanced against productivity needs.
Monitoring multiple networks
There’s also the question of your wider IT. IIoT ecosystems rarely run on one simple network. Each device could potentially span IT systems, OT devices, wireless connections, cloud providers, and vendors.
This makes every single one a potential entry point, in theory. Keeping a keen eye on multiple secure networks might be hard work, but it’s necessary for protecting wider environments. Things like shared monitoring and unified processes make it easier to spot threats before they spread.
Cyber security know-how
A key challenge of modern business is that cyber security skills are in short supply. Smaller industrial organisations can find it challenging to hire or retain the right talent. That’s especially true when budgets are tight.
There are many ways to address this. You might identify the gaps you face, then selectively hire based on that. Another common way is to outsource to an expert cyber security partner, bringing in strong IIoT security knowledge in a cost-effective way.
Key steps to securing your IIoT environment
Building security into your IIoT environment takes a layered, consistent approach that takes in everything from people and processes through to technology.
1. Get the full picture
First, you’ll need to get full visibility over your systems and the challenges you might face. It’s an excellent idea to conduct a complete inventory of every connected device, from sensors and controllers to cloud platforms and vendor portals.
Note down important elements like firmware, protocols, and software versions. Then, once you’ve got the full picture, you can highlight outdated systems and see where attackers might exploit weaknesses.
2. Understand who can access your devices and how
Now you know about every device, treat each one as a potential entry point to your business. There are quick wins here. Things like manufacturer default usernames and passwords must be changed immediately, and third-party vendor access needs strict oversight.
It doesn’t matter if your staff or third-party partners work remotely or on-site, you should apply strong authentication and log all activities. This will give you ultimate control over who can reach critical systems and how.
3. Segment distinct networks
Once you know your devices and who can access them, you can separate them into zones. Doing so is a good idea because one singular network that contains all devices makes it easy for attackers to move around undetected.
Instead, you can segment your IT and OT environments, then get deeper beyond those (if required). Tools like firewalls, VLANs, and DMZs help you create virtual walls that limit exposure of key data across networks.
4. Go zero-trust by design
Once your network segments are in place, you can tightly control who can access what. A good starting point? Never assume trust. With zero-trust, every device, user and request must prove legitimacy and a real need before being granted access to any key device or data store.
Techniques like least-privilege access and multi-factor authentication can help you keep key information on a need-to-know basis. In this way, zero-trust essentially shrinks your potential attack surface, minimising the chances of attackers exploiting stolen credentials or compromised devices.
ZTNA is no longer a luxury, it’s a necessity for modern enterprises. With users accessing systems from everywhere and third-party vendors increasingly integrated into core operations, traditional perimeter-based security simply doesn’t cut it.
Zero Trust flips the model: no user, device, or connection is trusted by default. By continuously verifying identity, enforcing least privilege access, and monitoring behaviour, ZTNA ensures that access is secure, contextual, and tightly controlled. It’s the foundation for resilient, scalable security, especially in environments where third-party risk is a growing concern.
We always recommend a layered, Zero Trust approach, combined with real-time monitoring, secure connectivity, and strong governance is essential to building operational resilience. We champion a unified, secure-by-design strategy that empowers manufacturers to innovate without compromise.
5. Build layers of protection
Once your initial protections are in place, you can add to them to increase your chances of staying safe. There are some sections of your business where one control is never enough.
So, think about where you could apply multiple layers of defence. Then, use firewalls, intrusion detection, endpoint security, and physical safeguards such as access controls and locked cabinets.
6. Keep everything up to date
Of course, the rules of the cyber security game are always changing. New tech means better productivity, but also new challenges. That’s why patch management is a critical task for your IIoT security.
If you leave outdated firmware operating for too long, that becomes an entry point. Instead, you can create a patching maintenance plan to keep everything secure against the latest threats. It’s a good idea to prioritise high-risk systems and test updates before you roll out. In some cases, you might also spot the need to replace severely outdated devices, saving you trouble before it happens.
7. Address governance and compliance
There are also several important compliance matters to address. Some come with potentially eye-watering fines, which is enough for many to keep up with them. But they’re also a chance for you to keep everything running at its best.
You can use governance, risk, and compliance frameworks to standardise practices across your IT and OT environments. These best practices will make meeting industry standards much more manageable, building good habits across your business.
8. Understand your systems and spot opportunities to improve
Similarly, if you want your IIoT security to be the best, you’ll probably need to make changes at some point. You might spot an opportunity to improve, or you may implement new technology or work with a new partner that requires specific guarantees.
To manage this, things like audits, penetration testing, and automated monitoring will give you chances to strengthen controls. There are also tools with real-time alerts that help you act on threats before incidents escalate. In this way, IIoT security improvement should be an ongoing project.
9. Be prepared to address incidents should they happen
Finally, it’s absolutely essential to prepare for all eventualities. There’s always a small chance that even the best defences can be breached.
Having an incident response strategy helps you plan who does what, should a system breach happen. Key people will know exactly what steps to take. While it can be a daunting task, preparing for an incident makes it possible to respond quickly and recover effectively.
Strong defences are vital, but resilience comes from readiness. Even with robust security controls in place, no system is immune to risk. That’s why a well-defined incident response strategy is just as critical as prevention. It ensures that when the unexpected happens, your team isn’t scrambling, they’re executing. By combining proactive protection with reactive preparedness, organisations can minimise disruption, protect reputation, and recover with confidence.
How Nasstar can help
IIoT security is the key to safe, efficient, and productive modern operations. An effective plan should combine layers of protection with tools like controlled access and real-time monitoring. The result is improved daily operations and reduced risk to your business.
At Nasstar, our expert team have years of experience in securing complex IT and OT environments across industries. If you need full managed services or targeted support, we can help strengthen your IIoT security posture to protect your key assets.
