The French government’s internal messaging tool, Tchap, victim of a data breach, does not know if any data was compromised.

The Tchap chat application, reserved for the French government, was hacked via a stolen valid account, the attacker claims that 13.5 GB were exfiltrated
The alleged haul includes 73,000 accounts, over 640,000 messages, over 800 chat rooms; encrypted private chats, public rooms no
ANSSI and DINUM investigate amid wider alerts on spying on messaging applications targeting the State

A chat application used exclusively by French officials was reportedly hacked and hundreds of thousands of messages exfiltrated. Authorities are now investigating the allegations.

Already in 2025, French Prime Minister François Bayrou banned the use of foreign chat applications, such as WhatsApp or Signal, for professional communication. Instead, employees were asked to use Tchap, an instant messaging and collaboration tool developed by DINUM, the French government’s digital affairs department, and ANSSI, the French cybersecurity agency.

The app is a fork of Riot and only available to users with a .gov address. Apparently, the app has over 300,000 monthly users, along with over 500,000 downloads on Google Play Store.

“misery” claims the rupture

A threat actor going by the alias “misere” recently took to the dark web to claim responsibility for the attack, claiming to have used social engineering to exfiltrate 13.5GB of data from the app.

Among the stolen data are 73,467 user accounts, 643,459 messages, 876 chat rooms with message history and 59,386 shared media files. They also claimed to have accessed chat rooms involving staff from several French ministries.

Meanwhile, ANSSI confirmed that the application had suffered a security breach, saying that initial reports pointed to valid account theft. The agency said private conversations in the app are encrypted, but public conversations are not.

DINUM added that it is currently investigating the incident.

In March 2026, the General Intelligence and Security Service (AIVD), the main civilian intelligence and security agency of the Netherlands, warned of a major cyberespionage campaign by Russian spies, in which they are attempting to access Signal and WhatsApp accounts belonging to dignitaries, military personnel and civil servants, including Dutch government employees.

A few weeks later, the FBI and CISA warned of the same thing, calling on US government employees to be careful with their mobile apps.

Via Cybernews