French Bank Crédit Mutuel Arkéa Confirms Cyberattack with Blockchain Investigation Estimating $133 Million in Losses

Crédit Mutuel Arkéa has confirmed it suffered a cyberattack resulting in fraudulent transactions. In a statement, the French banking group said the incident is contained and operations have been gradually restored, without disclosing the financial volume involved.

The bank did not reveal the attack's entry point, the exploited vulnerability, or whether stolen credentials were used. No responsible party has been identified by the institution or notified authorities, and public reports mention the group BREEZE COMET only as background context without evidence linking it to the incident.

The circulating loss estimate originates from blockchain investigator ZachXBT, who initially described the victim only as an unidentified European institution. According to him, over US$ 106 million departed on November 1 and another US$ 27 million raised the total beyond US$ 133 million. The investigator classifies these figures as investigative estimates rather than verified bank losses.

The described money trail passes through cryptocurrency exchanges. The amounts reportedly left in USDC and USDT, were converted to Ethereum, moved across different blockchains, and finally exchanged for Monero, a cryptocurrency designed to complicate tracking. ZachXBT noted that the total could increase if over-the-counter trades outside the mapped flows exist.

The gap between the bank's confirmation and the open investigation's estimates forms the central point of the case. The statement acknowledges fraudulent transactions without providing a figure, while blockchain tracing points to a nine-digit amount without official verification.

Among measures declared by the bank are temporary suspension of certain transactions, system verification, strengthened security controls, and notification of regulatory and supervisory authorities. The group stated that customer assets were not affected, some clients experienced transfer delays, and affected amounts are still being assessed without threatening the bank's financial stability.

Public reports link the fraud to Fortuneo, the group's digital bank, a connection the institution has not confirmed. The bank advised customers to distrust any contact requesting data, noting that such incidents are often followed by phishing attempts leveraging the news coverage. The group urged clients not to share passwords, card details, or SMS codes through any channel.