The German military has suspended the use of drones manufactured by Quantum Systems following a major cyberattack on the company. The German firm also supplies unmanned aircraft to Ukrainian forces, the Financial Times (FT) reports.

Hackers gained access to a Quantum Systems server and exploited it to distribute a malicious file to the manufacturer’s customers. In response to the security breach, the Bundeswehr halted the operation of drones produced by the company.

The individuals or groups responsible for the attack have yet to be identified. No information about those behind the breach has been made available.

Quantum Systems has a significant presence in Ukraine, where more than 200 of its employees are currently working. The German manufacturer is also involved in three joint ventures with Ukrainian companies. These facilities produce attack drones and interceptor UAVs.