Secure the Unpatchable: When Hackers Take Control of Refrigerators, How Do We Protect Devices That Can't Be Patched?

Hundreds of supermarkets in France recently faced an unusual cyberattack. The targets weren't payment systems or confidential business data. They were refrigerators and freezers.

According to BBC News, attackers compromised remote management software used to control refrigeration systems across several major French supermarket chains, including Carrefour, Intermarché, and Coopérative U.

The attackers manipulated refrigeration operations, causing temperatures to rise dramatically. Intermarché reported that some refrigeration units reached 50°C and remained at elevated temperatures for approximately six hours overnight.

Large quantities of refrigerated and frozen food had to be discarded, with total losses potentially reaching millions of euros.

But perhaps the most important detail in this incident was revealed by Danfoss, one of the technology providers involved.

Some affected refrigeration units were older models whose security software could not be updated to address an identified vulnerability.

In other words, businesses may have been aware of the security risks but unable to eliminate them through conventional software updates.

This highlights one of the most fundamental challenges in operational technology (OT) security:

What happens when equipment can't be patched, but operations can't stop?

1. The Equipment Still Works. The Security Updates Have Stopped.

In traditional IT environments, addressing a security vulnerability often means updating the operating system, installing a patch, or replacing the affected device.

In OT environments, things are rarely that simple.

Industrial controllers, semiconductor manufacturing equipment, medical devices, building management systems, and refrigeration systems are designed for long operational lifespans.

A machine may remain in service for 10, 15, or even 20 years.

However, the operating systems, firmware, and control software running these machines may no longer receive security updates.

Some equipment has reached end-of-support. Other systems cannot be easily updated because of compatibility requirements, operational constraints, or certification considerations.

Many legacy devices also cannot support modern endpoint security agents.

And businesses cannot simply shut them down.

For supermarkets, refrigeration downtime means spoiled inventory.

For hospitals, medical equipment downtime may affect patient care.

For semiconductor manufacturers, stopping a production line can result in substantial financial losses.

These machines were built to last. But their operational lifespans have often outlasted their cybersecurity support.

This is not an isolated problem. It is a growing reality across industries that depend on operational technology.

2. Connectivity Has Changed the Risk

Historically, many industrial systems operated in relatively isolated network environments.

Today, digital transformation, remote maintenance, centralized monitoring, and AI applications are connecting more operational equipment to enterprise networks and external platforms.

These connections provide tremendous business value.

Supermarkets can monitor refrigeration equipment across hundreds of locations. Equipment manufacturers can troubleshoot machines remotely. Factories can collect real-time operational data to improve efficiency.

But every new connection may also introduce a potential attack path.

The French supermarket incident demonstrates what can happen when cyber threats reach physical operations.

When attackers gain access to equipment management capabilities, the consequences extend far beyond traditional IT security.

A compromised refrigeration system can create food safety risks.

A compromised industrial controller can interrupt manufacturing.

A compromised building management system can disrupt critical infrastructure.

As IT and OT become increasingly connected, cybersecurity must protect not only information, but also the physical operations businesses depend on.

3. Unpatchable Doesn't Have to Mean Unprotected

Organizations operating legacy OT equipment often face a difficult choice.

They know vulnerabilities exist, but they cannot easily patch, replace, or shut down the affected systems.

However, protecting vulnerable equipment does not always require modifying the equipment itself.

If you can't patch it, protect the connections around it.

This is where Zero Trust and network micro-segmentation can make a difference.

Consider a refrigeration controller.

Under normal operating conditions, it may only need to communicate with designated management servers, monitoring platforms, and authorized maintenance systems.

But should every device on the corporate network be able to access that controller?

Should any remote system be allowed to connect to its management interface?

The answer is no.

Network micro-segmentation allows organizations to establish precise access policies based on legitimate operational requirements.

Only necessary communication is permitted. Unnecessary connections are restricted.

Even when the equipment itself cannot be patched, organizations can implement additional security controls at the network layer.

This approach, known as a compensating security control, is an important part of protecting legacy OT environments.

4. How Janus Cyber Helps Secure the Unpatchable

At Janus Cyber, we focus on making network security practical for environments where traditional endpoint protection is difficult or impossible to deploy.

Our flagship solution, netKeeper, uses AI-assisted automated network micro-segmentation to help protect connected IT and OT devices.

Designed with a transparent inline architecture, netKeeper does not require software agents on protected equipment or modifications to existing operating systems and firmware.

Its protection approach consists of three steps.

Step 1: Learn Normal Communication Behavior

AI-assisted traffic analysis identifies devices and their normal network communication patterns, helping establish a baseline of operationally necessary connections.

Step 2: Build Allowlist-Based Access Policies

Based on observed behavior and validated operational requirements, netKeeper helps establish policies that permit necessary communications while restricting unnecessary network access.

Step 3: Enforce Network Access Control

Once policies are validated and protection is enabled, netKeeper blocks unauthorized network connections, reducing unnecessary exposure and opportunities for lateral movement.

This approach is particularly relevant for legacy industrial equipment, medical devices that cannot support security agents, semiconductor manufacturing systems, and other critical OT assets that cannot easily be updated.

Network micro-segmentation is not a replacement for vulnerability remediation or application-level security. If an attacker compromises an authorized management system and sends malicious commands over an approved connection, additional safeguards are still required.

However, by limiting unnecessary connectivity, organizations can significantly reduce their attack surface and prevent many unauthorized network access paths.

Protecting equipment doesn't always mean changing the equipment.

5. From Reactive Patching to Proactive Protection

The French supermarket incident raises three important questions for every organization operating connected OT equipment.

First: Do we know which devices can no longer receive security updates?

Organizations may closely monitor patch management for IT assets while lacking visibility into the firmware versions, support status, and known vulnerabilities of their OT equipment.

Second: Do we know exactly who and what these devices communicate with?

Which network connections are truly necessary? Which are legacy configurations, overly permissive access paths, or simply no longer required?

Third: If one system is compromised, what prevents attackers from reaching other critical equipment?

Without appropriate network access controls, a compromised device or management system may become a pathway to other operational assets.

These questions matter far beyond the retail industry.

Hospitals, semiconductor fabs, manufacturers, energy providers, logistics operators, and smart building operators all face similar challenges.

Patching vulnerabilities and replacing unsupported systems should remain part of long-term security planning.

But when equipment cannot be immediately updated or replaced, organizations cannot afford to wait.

They need security controls that work with existing infrastructure, minimize operational disruption, and continuously enforce appropriate network access.

6. Secure the Unpatchable. Keep Operations Running.

The French supermarket incident reminds us that cyberattacks do not need to steal sensitive data to cause millions in financial damage.

Sometimes, changing the operating parameters of a physical device is enough to disrupt an entire business.

As operational technology becomes increasingly connected, unpatchable equipment will remain a persistent challenge.

We cannot expect every machine to receive security updates indefinitely. Nor can we ask businesses to shut down critical operations whenever a vulnerability is discovered.

But we can rethink how those machines are protected.

By extending security beyond the endpoint to the network connections surrounding it.

By moving from manually configured network controls toward more automated, precise, and enforceable access policies.

We can't patch every machine. But we can control who talks to it.

This is the philosophy behind Janus Cyber.

Secure the Unpatchable.

Keep critical equipment running. Keep critical operations protected.

About Janus Cyber

Janus Cyber specializes in AI-assisted automated network micro-segmentation, helping organizations implement Zero Trust network access controls across IT, OT, and legacy environments.

Its flagship solution, netKeeper, learns normal network communication patterns, establishes allowlist-based policies, and enforces network access controls to reduce unauthorized connectivity and lateral movement risks — without installing agents on protected devices.

Janus Cyber — Safer with Less Effort.

Reference: BBC News — Cyberattack affecting French supermarket refrigeration systems