The hack of the bitcoin network was only discovered after a group of hackers stole around 50 BTC, the equivalent of about $10 million, from a Bitcoin address, according to a report by Reuters.
The hack was discovered on Tuesday, with the money being spent on a new wallet that was sent to an address that was linked to an account in Hong Kong.
Bitcoin exchanges have been offline for several days, with some saying that it’s a sign that hackers are planning a wider attack.
Bitcoin exchange Kraken said on Tuesday that it would temporarily suspend withdrawals for customers who have been affected by the hack.
“We’re currently investigating a potential cyber attack on the bitcoin blockchain,” the exchange said in a statement.
Kraken, which has about 2 million users, is one of the largest bitcoin exchanges in the world.
It said it has been investigating the attack and that it is “monitoring the situation.”
A spokesman for Kraken, who asked not to be named because the investigation is ongoing, told Reuters that the exchange is working with the U.S. Secret Service to identify the attackers.
The New York Times reported on Tuesday the hack was first reported by a hacker called Kallax, who claimed to have stolen the funds from a bitcoin address in Hongkong.
Kallax claimed that he was the rightful owner of the funds and that the hacker had not stolen the bitcoins, according the Times.
It is unclear if the attacker was connected to the cyber attack.
Reuters has not yet released any details about the attack.