French blood banks operated by the French Blood Establishment (EFS) were hit by a cyberattack on Monday targeting refrigeration systems, the organization confirmed Wednesday. Hackers compromised cold storage units at three EFS sites operated by external providers, raising temperature and defrost thresholds to excessively high levels.

The units stored blood products, plasma for transfusions, medicinal products, and biobank samples. Surveillance systems triggered rapidly, and affected equipment was either brought under control or taken offline. No blood products or samples were lost, with materials quickly transferred to other facilities, the EFS said.

The attack mirrors a broader wave of cyberattacks across Europe. Hundreds of supermarkets in France, Belgium, Sweden, and Finland had refrigerators remotely hacked in recent weeks, causing potentially millions of euros in spoiled food losses.

The French Health Ministry said the situation is under control and blood supply safety was preserved through monitoring systems and precautionary measures. The EFS is coordinating with the French National Cybersecurity Agency (ANSSI) and the Ministry of Health, with increased equipment monitoring now in place.