French Tax Authority Breach: ANSSI Report Reveals Three Months of Undetected Intrusions

A report by the French National Cybersecurity Agency (ANSSI) confirms that the Direction générale des finances publiques (DGFiP) suffered a data breach between May and August 2026, which went undetected for three months. Attackers gained access by stealing credentials from personal computers belonging to agency staff, rather than through sophisticated technical exploits. Approximately 14 GB of data was exfiltrated, raising concerns regarding the security of taxpayer information as crypto assets are increasingly reported to tax authorities under DAC8.