French bank Crédit Mutuel Arkéa seeks to recover funds after €100mn hack

French bank Crédit Mutuel Arkéa is seeking to recover some of the estimated €100mn that hackers stole this week, a rare attack that raided the institution’s own account.

Crédit Mutuel Arkéa said on Wednesday that the incident had now been controlled and that no customer accounts were affected. The hackers did not go through any regional banking networks or subsidiaries, it added.

The hackers converted the stolen money into crypto and moved it through various crypto platforms, according to blockchain analysis company Bitquery, in a technique highly similar to the flow of funds stolen from crypto exchange Binance last week.

“This was a sophisticated external attack, which has now been contained,” the bank said, adding that it did not believe human error was to blame. “The attackers gained access through the platform of one of our service providers, thereby reaching Crédit Mutuel Arkéa directly.”

The hack comes at a time when companies are on high alert for cyber security breaches as the advent of powerful AI models makes it easier for criminals to penetrate defences. Last week, a record $6.3bn was stolen from Binance, the world’s biggest crypto exchange, in a sign of how hackers are targeting financial institutions.

France has been hit by cyber attacks on several fronts in recent weeks. An attack on hundreds of French supermarkets sabotaged freezers by manipulating their temperature controls, exposing security vulnerabilities in software supplied by refrigeration equipment manufacturers to retailers including Carrefour and Intermarché.

Three French blood-storage facilities were targeted by hackers this week, marking an apparent expansion of the attacks into the healthcare sector.

At a conference on Thursday held by banking regulator ACPR, French central bank governor Emmanuel Moulin said that financial institutions should seek to benefit from the “promising use cases” offered by AI, but also had to manage its potential downsides.

“AI also carries with it risks, as we have seen in recent days, and requires massive investments to fight against cyber security risk and cybercrimes,” Moulin said.

The bank said the final cost of the hack had not been determined since it was still trying to recover some funds, but that the “sums involved are in no way large enough to jeopardise Crédit Mutuel Arkéa’s financial health or strength”.

Crédit Mutuel Arkéa is a midsized French banking group headquartered in Brittany with 5.6mn customers, about 12,000 employees and €212bn in assets at the end of 2025. It also owns Fortuneo, one of France’s leading online banks.

A theft of €100mn would be equivalent to about one quarter of Arkéa’s 2025 net profit of €450mn, although the losses could end up being lower, the bank said.

The hackers first moved the funds on to several crypto exchanges, then withdrew them into 17 crypto wallets. They later used decentralised finance platforms to convert most of the funds into ethereum, the world’s second-biggest cryptocurrency, which cannot be frozen.

Bitquery said on Thursday that $21.6mn worth of ethereum was still held in crypto wallets linked to the thieves, and $12.3mn was held in DAI, a stablecoin that also cannot be frozen. The rest of the stolen funds had been moved via crypto exchanges and other platforms that need no accounts or identity checks.

Gérôme Billois, a cyber security expert at consultancy Wavestone, said the hack of an international bank such as Crédit Mutuel Arkéa was “really, really unusual” and a “huge event” for the financial industry.

Successful financial hacks of big banks are rare. In 2016, North Korean hackers stole $81mn from Bangladesh’s central bank. Billois said the Arkéa attack appeared to be unprecedented in Europe.

“It looks like a very determined and very precise cyber attack, which is quite unnerving,” he said.