French Tax Data Theft Using Stolen Staff Passwords Went Undetected for Seven Weeks

French Tax Data Theft Using Stolen Staff Passwords Went Undetected for Seven Weeks Swati KhandelwalSep 29, 2026Data Breach / Network Security An attacker used stolen passwords of staff at France's tax administration to take tax data on hundreds of thousands of taxpayers and businesses in June and July. Neither the tax administration nor France's national cybersecurity agency saw the data leave. The attack was not sophisticated, the agency, ANSSI, says in a report (in French) published on Tuesday: it worked because of weak login protection, poorly separated networks and gaps in monitoring. The tax administration, known as the DGFIP, runs France's tax website, impots.gouv.fr. The data came from E-Contact, the tool taxpayers use to message the tax administration. The stolen…