Cryptocurrency exchange Binance, which is registered in Malta, has confirmed a “large scale” data breach, in which hackers stole more than €35 million in cryptocurrency

In a statement, the company said hackers stole API keys, two-factor codes and other information in the attack.

Binance, the world’s largest cryptocurrency exchange by volume, said the theft impacted about 2 percent of its total bitcoin holdings.

Binance traced the cryptocurrency theft to a single wallet.

“All of our other wallets are secure and unharmed,” said the statement.

“The hackers had the patience to wait, and execute well-orchestrated actions through multiple seemingly independent accounts at the most opportune time,” the statement said. “The transaction is structured in a way that passed our existing security checks. It was unfortunate that we were not able to block this withdrawal before it was executed.”

“Once executed, the withdrawal triggered various alarms in our system. We stopped all withdrawals immediately after that,” the statement said.

Binance said its secure asset fund for users (SAFU) will cover user losses.