French Government’s Tchap Messaging Platform Breached via Compromised Account

French authorities are investigating a confirmed account compromise on Tchap, the French government’s encrypted Matrix-based messaging platform. ANSSI detected suspicious activity; DINUM blocked the compromised account and notified CNIL and users. A claimed attacker says social engineering enabled access to one shard and alleges exfiltration of ~13.5GB of files, ~650,000 messages, and metadata for ~73,000 accounts, including leaked credentials in a PowerShell script; these findings are under investigation and not fully verified.