The Internet of Things has fundamentally changed how businesses operate. From smart thermostats and connected printers to industrial sensors and fleet tracking systems, IoT devices now sit at the heart of modern operations. But with that connectivity comes a significant challenge: keeping all of those devices — and the data flowing through them — genuinely secure.

Cyberattacks targeting IoT devices have surged dramatically in recent years. According to a 2023 report by Nokia, IoT devices now account for over 33% of all infected devices detected on mobile networks — up from just 16% in 2019. For businesses, this isn’t just an IT headache. A compromised IoT device can serve as a backdoor into your entire network, exposing sensitive customer data, operational systems, and financial records.

This article breaks down the most important IoT security best practices businesses should understand and implement, without the jargon and without the fluff.

Why IoT Security Deserves Serious Attention

It’s tempting to think of IoT devices as minor additions to your network — a smart coffee machine here, a connected HVAC controller there. But that kind of thinking is exactly what cybercriminals count on. Each connected device represents a potential entry point, and many of them are designed with convenience in mind rather than security.

The infamous Mirai botnet attack in 2016 demonstrated this clearly. Hackers exploited thousands of poorly secured IoT devices — including cameras and routers — to launch one of the largest distributed denial-of-service (DDoS) attacks ever recorded, taking down major websites including Twitter, Netflix, and Reddit. The devices themselves weren’t the targets; they were the weapons.

For businesses specifically, the stakes are even higher. Regulatory frameworks like the UK’s Data Protection Act 2018 and the EU’s GDPR hold organisations accountable for how personal data is handled and protected. A breach stemming from an unsecured IoT device can carry significant financial and reputational consequences.

The Most Common IoT Security Risks Businesses Face

Default Credentials Left Unchanged

Many IoT devices ship with factory-set usernames and passwords — often something as basic as “admin/admin” or “admin/password”. If these aren’t changed immediately upon deployment, they’re essentially an open door. Automated bots continuously scan the internet for devices using default credentials, and they find them in alarming numbers.

Outdated Firmware and Software

Unlike smartphones and computers, IoT devices often don’t prompt users to update their software. Manufacturers may release security patches infrequently, or businesses may simply overlook the update process. Unpatched firmware is one of the most common vulnerabilities attackers exploit.

Lack of Network Segmentation

When IoT devices share the same network as critical business systems, a single compromised device can give an attacker access to everything. Without proper segmentation, your smart building sensor and your financial database might as well be sitting in the same room.

Weak Encryption or No Encryption at All

Some IoT devices transmit data without encrypting it, meaning that anyone monitoring the network can intercept and read that data. Others use outdated encryption protocols that are no longer considered secure.

What Risk Is Associated with Using Unauthorised IoT Devices?

Unauthorised IoT devices — sometimes called “shadow IoT” — are devices connected to a business network without the knowledge or approval of the IT department. Employees might plug in a personal smart speaker, a fitness tracker, or a cheap connected camera without realising the risk. These devices haven’t been vetted, are unlikely to meet the organisation’s security standards, and may not receive manufacturer support or patches. They can introduce malware, create backdoors, and expose the network to vulnerabilities that the IT team doesn’t even know to look for.

IoT Security Best Practices Every Business Should Implement

1. Conduct a Full IoT Device Inventory

You cannot protect what you cannot see. Before anything else, businesses should conduct a thorough audit of every device connected to their network. This includes everything from obvious devices like routers and IP cameras to less obvious ones like smart printers, building management systems, and even modern photocopiers. Network scanning tools can help identify devices that IT teams may not be aware of — including those unauthorised shadow IoT devices.

2. Change Default Credentials Immediately

Every IoT device should have its default username and password changed before it’s connected to the business network. Passwords should be strong, unique, and stored securely using a business-grade password manager. Where possible, enable multi-factor authentication (MFA) for device management interfaces.

3. Keep Firmware and Software Updated

Establish a regular patch management process that includes IoT devices. Subscribe to manufacturer security bulletins so you’re notified when new vulnerabilities are discovered. If a device no longer receives security updates from its manufacturer and cannot be replaced immediately, consider isolating it from sensitive network segments until it can be retired.

4. Segment Your Network

Network segmentation involves dividing your network into separate zones so that devices in one zone cannot freely communicate with devices in another. IoT devices should sit on their own dedicated network segment — often called a VLAN (Virtual Local Area Network) — that is isolated from systems containing sensitive business or customer data. This way, even if an IoT device is compromised, the attacker’s ability to move laterally through the network is significantly limited.

5. Disable Features and Services You Don’t Need

Most IoT devices come with a range of features enabled by default — remote access, Telnet, UPnP (Universal Plug and Play), and more. If your business doesn’t need these features, disable them. Every unnecessary open port or service is a potential attack surface. The principle here is simple: if you’re not using it, turn it off.

6. Use Strong Encryption for Data in Transit and at Rest

Ensure that all data transmitted by IoT devices is encrypted using current, robust protocols such as TLS 1.2 or 1.3. For devices that store data locally, check whether that data is encrypted at rest. If a device doesn’t support modern encryption standards, that should factor into your purchasing decisions going forward.

7. Implement Monitoring and Anomaly Detection

Once your IoT devices are secured and segmented, ongoing monitoring is essential. Security Information and Event Management (SIEM) systems can aggregate logs from across your network and flag unusual behaviour — for example, a temperature sensor suddenly attempting to communicate with an external IP address. Behavioural anomaly detection tools are becoming increasingly important as IoT fleets grow in size and complexity.

8. Establish a Clear Policy for Purchasing and Approving Devices

Before any IoT device is procured, it should go through a defined approval process that considers security features, manufacturer support policies, update frequency, and compliance with relevant standards. In the UK, the Product Security and Telecommunications Infrastructure (PSTI) Act 2022 sets baseline security requirements for consumer connectable products, which is a useful reference point. Policies should also explicitly prohibit employees from connecting personal devices to the business network without prior approval.

9. Plan for Device End-of-Life

IoT devices don’t last forever, and manufacturers eventually stop supporting older products with security patches. Businesses need a clear end-of-life policy that identifies when devices should be retired and replaced, and what to do with decommissioned hardware — including securely wiping any stored data before disposal.

10. Train Employees on IoT Security Awareness

Technology can only go so far. Human behaviour remains one of the biggest variables in any security strategy. Employees should understand why IoT security matters, what shadow IoT risks look like, and what to do if they suspect a device has been compromised. Regular, engaging security awareness training — not just an annual tick-box exercise — makes a genuine difference.

How to Protect IoT Devices from Hackers: A Practical Summary

Protecting IoT devices from hackers comes down to reducing your attack surface, maintaining visibility, and staying ahead of emerging threats. Practically speaking, that means:

• Changing default credentials on every device before deployment
• Keeping firmware updated and monitoring manufacturer security bulletins
• Segmenting IoT devices onto dedicated network zones
• Monitoring network traffic for unusual behaviour from IoT endpoints
• Disabling unnecessary features and closing unused ports
• Encrypting data in transit and at rest wherever possible
• Training staff to recognise and report potential security concerns

None of these steps require enterprise-level budgets. Many can be implemented with existing tools and sensible processes. The key is consistency — a single unsecured device can undermine an otherwise robust security posture.

IoT Cybersecurity: Looking at the Bigger Picture

IoT security doesn’t exist in isolation. It’s part of a broader cybersecurity strategy that includes endpoint protection, identity and access management, incident response planning, and ongoing risk assessment. Businesses that treat IoT security as an afterthought — bolted on once devices are already deployed — tend to find themselves playing catch-up when something goes wrong.

Standards and frameworks can provide useful guidance. The NIST Cybersecurity Framework, for example, offers a structured approach to managing cybersecurity risk across an organisation, and its principles apply equally well to IoT environments. Similarly, the ETSI EN 303 645 standard provides a baseline for IoT device security, covering areas like default password policies, vulnerability disclosure, and software update mechanisms.

For businesses operating in heavily regulated sectors — healthcare, finance, energy, or education — the stakes are particularly high. The education sector, for instance, often operates large numbers of connected devices across sprawling campuses with limited IT resources, creating a particularly complex environment for managing IoT security risks.

Conclusion

The growth of IoT in business environments shows no sign of slowing down, and neither does the ingenuity of those looking to exploit poorly secured devices. Understanding IoT security best practices isn’t optional for modern businesses — it’s a fundamental part of operating responsibly in a connected world.

The core principles are consistent: know what devices are on your network, secure them properly from the outset, keep them updated, segment them from critical systems, monitor them continuously, and ensure your people understand the risks. Businesses that apply these practices systematically are in a far stronger position to manage the threats that inevitably arise — and to respond effectively when they do.

IoT security is an ongoing process, not a one-time project. As device landscapes evolve and threat actors develop new techniques, security strategies need to evolve alongside them. Staying informed, staying vigilant, and treating security as an embedded organisational value rather than a compliance box to tick is what separates businesses that manage risk well from those that learn about it the hard way.