Unknown hackers are have stolen a large amount of Bitcoin cryptocurrency from Hong Kong based Binance, the online exchange said.
In announcing the theft, Binance chief executive Changpeng Zhao said the hackers withdrew just over 7000 Bitcoin in a single transaction.
Zhao said the hackers used phishing and viruses to obtain application programming keys and two-factor authentication, and possibly other information, from Binance staffers.
"The hackers had the patience to wait, and execute well-orchestrated actions through multiple seemingly independent accounts at the most opportune time.
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," Zhao said.
The value of the stolen Bitcoin amounts to approximately A$57.4 million, with the funds being taken from Binance's hot (network connected) wallet only.
While this amounts to just two per cent of Binance Bitcoin holdings, Zhao warned that thhere could be other accounts affected by the hack.
Zhao said that the hackers could still control certain user accounts, and could use them to influence crypto currency pricing.
To avoid price manipulation by the hackers, Binance has disabled withdrawals from the exchange currently.
Binance will use it Secure Asset Fund to cover the loss.