Massive Cyberattack on Naval Group Sparks National Security Fears in France

Naval Group, France’s largest shipbuilder and a cornerstone of European defense, has reportedly fallen victim to a significant cyberattack. A hacker group has claimed responsibility on a popular data leak forum, alleging access to critical assets, including source code for combat management systems (CMS) used in French submarines and frigates.

Headquartered in Paris, Naval Group employs over 15,000 people and generates more than $5 billion (€4.3 billion) annually. Its major stakeholders include the French government and defense technology firm Thales Group.

The breach is being called one of the most serious defense-related cyber incidents in France to date, with implications for national security. Rather than selling the stolen data, the attackers are said to be extorting Naval Group, threatening to release classified material if their demands are not met.

Leaked information reportedly includes CMS source code, technical documentation, internal network data, developer virtual machine access, and confidential communications. Some materials, including a 2003 video from a submarine monitoring system, have surfaced online. If authentic, the breach could expose critical defense capabilities to adversaries and require costly countermeasures.

Thales faces potential reputational and operational fallout as a primary shareholder. Dassault Systèmes, which supplies Naval Group with its 3DExperience software platform, may also be scrutinized over its cybersecurity protocols.

Experts warn that hackers often exaggerate the impact of such breaches to increase pressure for extortion. While the full scope of the incident is not yet verified, early analyses suggest that at least some of the leaked data is genuine.

Naval Group, established in the 17th century and formerly known as DCN, has been central to France’s naval defense, including the construction of the nuclear aircraft carrier Charles de Gaulle. French authorities have launched a full-scale investigation into the breach.