Nicehash, one of the best-used cloud mining services, has seen its site breached and its payment system drained of about 4,700 BTC. At current prices above $14,000, the theft is worth more than $64 million.
Bitcoin wallets are usually a highly secure technology, but the hack may have included a sophisticated attempt to scam and steal wallet keys. The hack was " a highly professional attack with sophisticated social engineering," said Andrej P. Škraba for Reuters.
The Slovenia-based cloud service stated it would cooperate with local authorities. Nicehash needs the Bitcoin to repay users who offer up spare computing power for mining various coins. Nicehash acts as an intermediary for miners to sell idle equipment, while buyers choose the preferred coins trending at the moment.
As the value of crypto coins increases, more hackers are attacking wallets directly. But stealing the private key to a wallet may be a task requiring a gain of trust, to make a user provide their private key or access to the wallet.
Reddit users believe the hack may in fact be an internal affair, with no way to know for sure. Slovenian media have shown connections between the owners of Nicehas's capital and a recently arrested hacker, Matjaž Škorjanc.