A new wave of fridge cyberattacks hit supermarket refrigeration systems across five European countries, raising temperatures and causing food losses.

A new wave of fridge cyberattacks has affected supermarket refrigeration systems in several European countries. Fridges and freezers suddenly rose in temperature overnight, with some incidents suspected to be caused by hackers. On Monday, November 2, Ahold Delhaize and Colruyt reported an IT incident affecting dozens of stores in Belgium and Luxembourg. Swedish supermarket chains ICA and Coop also reported similar problems.

“Ahold Delhaize and Colruyt said on Monday that an IT ​incident overnight hit fridges and freezers in dozens of stores in Belgium and Luxembourg, while Swedish grocers ‌ICA and Coop reported similar temperature spikes, with one store blaming a cyberattack.” Reuters states.

“Problems were discovered at several grocery stores in Sweden overnight Monday.” reported Sweden Herald.

“We are aware that a limited number of stores were affected by an incident overnight that affected their refrigeration and freezer systems. Ica is providing support in handling the incident, Ica Group press officer Gustaf Nilsson tells TT.”

The latest incidents follow a similar wave of fridge cyberattacks in France last month. In mid-October, a large cyberattack hit the refrigeration systems of hundreds of French supermarkets, BFMTV revealed. The attackers targeted equipment from the Danish maker Danfoss that many French stores use to regulate their cold. Fresh and frozen stock was destroyed, and the Paris prosecutor says there were also fires.

The method is simple and nasty. Refrigeration systems have a forced defrost function that clears ice buildup, and the attackers appear to have triggered it remotely in a continuous mode, with a temperature setting of 50 degrees. The equipment heated for several hours instead of keeping goods cold, and when staff opened the fridges and freezers in the morning, a sector source told BFM, “a wave of heat” came out.

The attack caused fires and food losses. However, cybersecurity consultant Emil Olofsson of Integrity 360 told Swedish news agency TT that temperatures reached 80°C in some cases and several units caught fire. This figure differs from the one reported by police.

ICA Kvantum in Sjöbo said on Facebook that a cyberattack caused the refrigeration problems. ICA Hägerstensåsen in Stockholm was also reportedly affected. According to the Sjöbo store, the temperature inside its fridges and freezers rose to 50°C.

In Belgium, Delhaize detected unusual temperature increases in its refrigeration systems on Monday. Spokesperson Sarah De Meester said the company is investigating the incident.

Stephan Moelans, CEO of Sabcobel, the company that manages Delhaize’s refrigeration systems, told news agency Belga that hackers had switched the units’ evaporators to defrost mode. His office declined to comment to Reuters. Colruyt Group, which operates Spar stores in Belgium through a franchise system, said five stores had suffered attacks on their refrigeration systems. Meanwhile, Belgian newspaper Le Soir reported that dozens of Delhaize and Carrefour stores were affected.

It follows a similar attack in France last month. Police said hackers seized control of the cooling units at hundreds of supermarkets and raised temperatures as high as 50 degrees Celsius (122 Fahrenheit), which caused fires and food losses. Cybersecurity consultant Emil Olofsson of Integrity 360 told TT, Sweden’s news agency, that temperatures there reached 80 degrees and some units caught fire, a figure that differs from the police number.

In Belgium, Delhaize noticed temperature increases in its cooling systems on Monday, spokesperson Sarah De Meester said, and the company is investigating. Stephan Moelans, CEO of the refrigeration firm Sabcobel, which runs Delhaize’s systems, told the news agency Belga it was a cyberattack that switched the units’ evaporators to defrost mode. His office declined to comment to Reuters. Colruyt Group, which runs Spar stores in Belgium under a franchise system, said five shops had their fridge systems attacked, and Le Soir reported that dozens of Delhaize and Carrefour stores were affected.

Ahold also reported a cybersecurity incident to Dutch police last month, after it detected suspicious activity in its infrastructure. Nothing in the reporting ties that report to Monday’s incident.

In Sweden, John Billow, head of the national cybersecurity centre, told Reuters his team was working on several incidents involving refrigeration systems in grocery stores around the country. An ICA Kvantum store in Sjöbo said on Facebook that a cyberattack caused its problems, and an ICA store told its followers that its temperatures had been “hacked” overnight and set to 50 degrees. Fifty degrees is fine for a beach and poor for ice cream. That store later said it had opened.

At ICA Baronen in Stockholm, a notice said all the freezers were broken because of a cyberattack. The sales manager said the attack came at 2 a.m. and staff noticed it at 5:30 a.m. ICA Hägerstensåsen in Stockholm was reportedly hit too.

ICA said only a limited number of stores were affected and that it is helping them deal with the incident. However, press officer Gustaf Nilsson did not say how many stores were involved.

Coop told Swedish news agencies Aftonbladet and TT that six stores in central Sweden had similar problems. Press manager Carlos Cancino said it was still unclear whether any food would need to be thrown away or whether the refrigeration units had simply stopped working or had switched to heating mode. He also did not rule out further incidents affecting other stores.

An Estonian supermarket chain was also affected. Its refrigeration systems were reportedly set to 50°C, technology provider Kitman Coldtech told public broadcaster ERR. CEO Jann Mutso did not reveal the name of the supermarket chain, saying: “This is very recent. It happened this morning.”

How did the attackers get in? In France, Olofsson says they obtained login details for the control systems, which were exposed directly to the internet. He says the attack targeted a product that controls the cooling systems and that the hack isn’t very complicated, so amateurs may have carried it out.

Billow says Swedish authorities have noticed in recent weeks that quite a lot of exposed operational technology devices exist in Sweden, and they’ve been clear that these must be updated or patched.

Refrigerators and heating systems, security cameras and alarm networks were once largely mechanical, and now they can be monitored and controlled remotely. That gives cybercriminals new openings. Authorities haven’t said who was behind last month’s incidents, and nobody has claimed responsibility.

The Sweden Herald reported that the cause of the attacks on Swedish supermarkets remains unknown.

Update 20:00 Rome Time

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, fridge cyberattacks)

Ukraine warns that attackers can remotely access Dahua cameras and recorders via Easy4IP, viewing video and changing settings.

Ukraine’s cyber incident response team CERT-UA has warned about attackers taking over video surveillance systems made by Dahua. In its alert dated October 23, 2026, it reports unauthorized remote access to IP cameras and video recorders. The attackers have watched the live video, changed device settings and created accounts of their own. The alert doesn’t say who was targeted or how many devices are affected.

The attackers abused Easy4IP, Dahua’s cloud feature that lets users access devices remotely. When this feature is enabled, the camera or recorder connects to Dahua’s cloud and registers using its serial number. Anyone who knows the serial number may be able to access the device through the cloud, without needing an open port or a public IP address. This means the connection can bypass the protection normally provided by a router’s firewall.

As a result, a camera that isn’t directly exposed to the internet may still be at risk. CERT-UA warns that devices with Easy4IP enabled may be vulnerable even when they cannot be accessed directly from the internet.

“The main vector is the P2P/cloud access function (Easy4IP). The device independently initiates an outgoing connection to the manufacturer’s cloud infrastructure and registers in it by serial number. Access to the device is then established via the cloud by serial number, bypassing NAT and firewall, without published ports and a “white” IP address.” reads the report published by CERT-UA. “Thus, the lack of direct access from the Internet does not guarantee the security of the device with the active P2P function.”

Serial numbers follow predictable patterns, so attackers may be able to guess them automatically and check which devices are registered in the cloud. Simply keeping a serial number private isn’t enough to ensure security.

Once attackers connect to a device, they need to get past its login. They may try common or weak passwords or exploit security flaws in outdated firmware, especially CVE-2021-33044 and CVE-2021-33045. These two vulnerabilities allow attackers to bypass authentication without a password, so even a strong password won’t protect a device running vulnerable firmware.

There are three signs that a device may have been compromised. First, look for accounts you don’t recognize. Second, check for changed settings, including text added over the video image. However, the absence of these labels does not mean the device is safe. Third, check the audit logs for logins using Dahua’s DVRIP protocol from the local address 127.0.0.1, which can indicate access through the cloud service.

CERT-UA recommends four steps:

1. Turn off P2P and cloud access if you don’t use it.
2. Keep cameras off the internet. For remote access, use a VPN and allow only authorized IP addresses.
3. Check the account list for ones you didn’t create, and check which cloud accounts are linked to the device and disconnect unknown ones.
4. Update the software by hand to the latest version, and set up a regular update routine.

CERT-UA advises organizations that detect signs of unauthorized access to report them to cert@cert.gov.ua and check all Dahua devices on their networks, including those that may have been forgotten. The agency warns that all devices with active P2P functionality are at risk.

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, IP cameras)

Fortinet details ClingSTUN, a Linux backdoor exploiting unpatched IoT devices and abusing public STUN servers to route traffic past NAT.

FortiGuard Labs researchers spotted a Linux malware family they call ClingSTUN, and the name gives away its trick immediately. Instead of relying on a dedicated command server, the malicious code leans on STUN, the protocol that helps devices behind a router figure out their real public IP address. Video calling apps use it constantly, which means ClingSTUN’s network traffic hides inside something that already looks completely normal.

“ClingSTUN functions as a back-connect proxy backdoor, turning infected systems into remotely controlled proxy nodes. It abuses public STUN (Session Traversal Utilities for NAT) infrastructure to discover externally mapped IP addresses and ports, maintain NAT bindings, and improve connectivity between compromised hosts and remote operators.” reads the report published by Fortinet. “Because many of the STUN servers it contacts are legitimate public services, the resulting traffic easily blends with normal VoIP and WebRTC communications.”

The attack starts with a familiar problem: old, unpatched devices exposed to the internet. Fortinet first spotted the campaign exploiting a known command injection flaw in Hytec Inter routers. As the campaign evolved, the attackers changed their download infrastructure and expanded the list of vulnerabilities they were exploiting.

In the latest wave, they were targeting devices from more than a dozen vendors, including D-Link, TP-Link, Realtek and Linksys, as well as several DVR and IoT cloud platforms. Many of these devices are easy targets because they are rarely updated or closely monitored.

Once the attackers find a vulnerable device, a small downloader script installs the right malware version for its hardware. It supports common architectures such as ARM, MIPS, PowerPC and Intel.

The latest version also checks the device for other malware before installing itself. It scans mounted filesystems and kills suspicious processes running from temporary directories. In other words, ClingSTUN is not just trying to infect the device. It also tries to remove competing malware and take full control.

The persistence mechanism is almost old-fashioned in its simplicity. The malware copies itself into two separate locations, then appends itself to three different boot scripts so it survives a reboot no matter which startup path the device actually uses. It also walks through every running process, checks whether the command line matches what the process claims to be, and kills anything that doesn’t line up, which is both a defense mechanism and a fairly blunt way of eliminating rival malware fighting for the same compromised box.

Two details stand out as genuinely well thought through rather than copy-pasted from some other botnet’s source code. First, it opens the device’s watchdog timer and quietly disables it, so the device never auto-reboots itself out of the infection the way embedded hardware is designed to if something goes wrong. Second, once it’s running as root, it swaps its own process metadata for a copy of PID 1’s, the very first process the kernel starts, which makes a basic process listing show what looks like the init system instead of malware.

“After setting up persistence, ClingSTUN clears its original command-line arguments so that its command line appears empty in tools such as “ps.” It then checks whether it is running as root (UID 0).” reads the report. “If so, it copies selected process information files from “/proc/1/” to “/tmp” and bind-mounts “/tmp” over its own “/proc/” directory, concealing its process information behind metadata copied from PID 1.”

The STUN part is especially interesting because it helps ClingSTUN hide in normal network traffic. The malware sends standard requests to public STUN servers to find out its external IP address and port. These are the same services commonly used by VoIP and WebRTC applications.

Later versions reduced the number of STUN servers and required all connections to work, which suggests the attackers were improving reliability. Because the traffic goes to legitimate third-party services, it can be difficult for defenders to tell the difference between ClingSTUN activity and normal traffic from apps such as Zoom.

Command delivery itself still needs a human on the other end willing to send a 20-byte packet the right way.

“ClingSTUN establishes a UDP socket, binds to a random local port, and sends standard 20-byte STUN binding requests. It sends these to 24 public endpoints and ensures at least half succeed.” Fortinet states. “The third evolution reduced this to 13 endpoints and ensures every endpoint connection succeeds.”

A single control datagram can trigger ClingSTUN to open a fresh outbound TCP connection to an address the operator specifies, pull down a command over that connection, and execute it, which keeps the heavy lifting off the STUN channel and limits what shows up in any one place. The malware also carries hardcoded exploits for seven more vulnerabilities purely for spreading itself further, meaning every infected device doubles as a scanner looking for its next host.

Fortinet stresses that the STUN servers are not compromised or malicious. They are simply working as intended. These third-party services should not automatically be treated as attacker-controlled infrastructure.

“ClingSTUN’s exploitation of known, unpatched vulnerabilities reinforces the importance of consistent cyber hygiene.” concludes the report. “Organizations should inventory Internet-facing devices, track their firmware and support status, and promptly apply available security updates, prioritizing vulnerabilities known to be actively exploited.”

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, ClingSTUN)