The company's marketplace is now down, showing a maintenance message. This way, users can benefit from bitcoin mining without purchasing or operating the equipment themselves.
More than 4,500 bitcoins worth approximately $62 million at today's prices may have been stolen from the NiceHash exchange. Several reports from users noted that their Bitcoin wallets associated with NiceHash had been emptied.
NiceHash says it reached out to "to the relevant authorities and law enforcement".
The NiceHash team urged users to change their online passwords as a result of the breach and subsequent theft.
While the NiceHash operators seem honest with their statement, those words ring hollow for users that lost their accumulated BTC.
After a 12-hour service outage for 'maintenance, ' Nicehash just announced that last night it fell victim to a security breach. The company has paused operations for 24 hours while it figures out exactly how much was swiped and how it was taken.
"Our payment system was compromised and the contents of the NiceHash Bitcoin wallet have been stolen".
NiceHash would only go so far as to state that it is "working to verify the precise number of BTC taken".
We are now investigating the nature of the incident and, as a result, we are stopping all operations for the next 24 hours.Clearly, this is a matter of deep concern and we are working hard to rectify the matter in the coming days.
The company added that it was "fully committed to restoring the NiceHash service with the highest security measures at the earliest opportunity", but having experienced such a significant blow, how it will manage to return to trading without the ability to provide funds to those using its service is not clear at this point.
"While the full scope of what happened is not yet known, we recommend, as a precaution, that you change your online passwords", they wrote in the statement.