Hackers have robbed bitcoin mining site NiceHash, with customers speculating that over $70 million may have been stolen. NiceHash confirmed the breach on Wednesday and said it would stop operations for the next 24 hours.
"Importantly, our payment system was compromised and the contents of the NiceHash bitcoin wallet have been stolen," the service said. "We are working to verify the precise number of BTC taken."
The Slovenia-based NiceHash acts as a digital marketplace for bitcoin enthusiasts to buy and sell computing power to mine the cryptocurrency. It claims to have over 280,000 daily active users.
However, the rising price of bitcoin has made services like NiceHash a major target for hackers. On Thursday, the cryptocurrency's price was reaching $19,000 for a single bitcoin.
NiceHash customers on Reddit are grumbling about the breach and circulating a bitcoin wallet address that may have been involved in the hack. That wallet contains 4,736 bitcoins or $76 million.
Recommended by Our Editors
NiceHash's head of marketing also told Reuters that about 4,700 bitcoins had been stolen in the breach.
It isn't clear if NiceHash lost all its bitcoin, but the site's temporary closure doesn't bode well for its customers. "I will lose 2 bitcoin so I definitely hope this is not an exit scam or hack of all funds," wrote one user on Reddit. Others said they had been mining bitcoin through the service for months, but had yet to cash out.
The NiceHash breach underscores that investing in bitcoin does carry some risks. Last year, bitcoin exchange Bitfinex lost what was then over $60 million in a separate hack.
On Thursday, bitcoin exchange Coinbase also went down, tweeting that it was experiencing record traffic.