French bank Credit Mutuel Arkea says about €100 million (about $112.61 million) is missing and it cannot yet say how much it will be able to recover after a cyberattack this week, in a rare successful heist against a large financial institution.

The attack took place on Wednesday 4 November. The attackers used an account belonging to Credit Mutuel Arkea to carry out fraudulent transactions to other banks, possibly allowing the funds to be converted into cryptocurrency through specialised platforms. The bank said the attackers reached it through a third-party service provider's platform, which it declined to identify. The hack did not involve customer accounts, and customer assets were not affected, although the bank temporarily suspended some transactions as a precaution, causing delays to some transfers.

A larger figure, unconfirmed

Blockchain investigator ZachXBT had earlier put the suspected theft at more than $133 million (about €118 million), after first flagging more than $106 million in suspicious withdrawals on 2 November and then tracing a further $27 million. That figure is unconfirmed: the bank declined to confirm the €118 million figure and said it could only validate the order of magnitude, with part of the funds blocked and recovery work under way.

The bank rejected media reports that its online banking subsidiary Fortuneo was the entry point, saying there had been no entry through Fortuneo and that neither the division nor its customers' accounts were involved. It has informed the European Central Bank, French banking supervisors and prosecutors. The Paris prosecutor's office said its cybercrime unit received a complaint on Wednesday and immediately opened an investigation into an organised attack on an automated data processing system. Brittany-based Credit Mutuel Arkea has more than 5.8 million customers and €211.5 billion in assets.

Sources: Reuters, French bank Credit Mutuel Arkea says €100 million missing after cyberattack, 5 November 2026; Unchained, Crédit Mutuel Arkéa Says Attackers Drained Its Own Account and May Have Cashed Out in Crypto, 5 November 2026.