Overview

• The Hauts-de-Seine department confirmed a significant cyberattack on May 20, 2025, which has paralyzed its information systems and usual communication channels.
• All IT systems and communication means have been disabled indefinitely as a precautionary measure while recovery efforts are underway.
• Internal IT teams and external service providers are working to assess the impact, protect sensitive data, and restore access to networks and applications.
• Authorities have not yet identified the perpetrators or the methods used in the attack, and investigations are ongoing.
• This incident follows a series of cyberattacks targeting Hauts-de-Seine and its communes since 2023, highlighting persistent vulnerabilities in local government systems.