Unknown hackers have stolen 7,000 bitcoins ($40.4 million) from Binance, the world’s largest cryptocurrency exchange.

The data breach and theft were detected Tuesday at 12:15 p.m. EDT. The attackers also stole user application processing interface keys, two-factor authentication codes and potentially other information.

According to a security breach update from Binance, the hackers used a variety of techniques, including phishing, viruses and other attacks to gain access to the information and steal the bitcoins.

The company noted that the 7,000 bitcoins were stolen in a single transaction and that the funds affected only Binance’s BTC hot wallet. Other wallets remain secure and unaffected.

“The hackers had the patience to wait and execute well-orchestrated actions through multiple seemingly independent accounts at the most opportune time,” Binance said. “The transaction is structured in a way that passed our existing security checks. Once executed, the withdrawal triggered various alarms in our system. We stopped all withdrawals immediately after that.”

The good news for customers is that the funds will be covered by Binance’s Secure Asset Fund for Users, an emergency insurance fund Binance established last year to cover any losses if the service is hacked.

Binance went on to note that it will be undertaking a “thorough security review” over the next week to identify what when wrong and to prevent it from occurring again. Withdrawals and deposits through the exchange remain suspended during the review to assure that the service is secure.

This is a minor blow for Binance at a time the company has been riding high of positive news. In March it was reported that Binance Coin, Binance’s own cryptocurrency, had doubled in price and was being hailed as the next bitcoin. In April the company launched its own custom blockchain to take on Ethereum.

As is to be expected when a leading cryptocurrency exchange reports that it has been hacked, markets were spooked by the news. The price of bitcoin dropped by as much as $200 before recovering slightly as investors realized the hack was relatively minor given Binance’s overall size.

Bitcoin was trading at $5,789.60 as of 11:30 p.m. EDT, down from a high of $5,937.50 earlier in the day.

Image: 149561324@N03/Flickr