Nearly $70 million worth of bitcoin was stolen from a cryptocurrency-mining service called NiceHash following a security breach, causing the company to halt operations for at least 24 hours.
“Clearly, this is a matter of deep concern, and we are working hard to rectify the matter in the coming days,” NiceHash said in a statement on its Facebook page.
Andrej P. Škraba, head of marketing at NiceHash, confirmed to The Wall Street Journal that approximately 4,700 bitcoin BTCUSD, had been stolen from a bitcoin wallet, an online account that stores the digital currency. Bitcoin wallets, like other online bank accounts, have been targets of hackers in the past.
“It was a professional attack,” Škraba said. He declined to elaborate further, saying more information will be revealed later.
Shuttered bitcoin exchange MtGox has found almost 200,000 bitcoins which it believed were lost, according to the company’s CEO Mark Karpeles.
The money was sitting in a wallet which the firm thought no longer held bitcoins. However, following the application for civil rehabilitation (a Japanese legal procedure analogous to bankruptcy), “these wallets were rescanned, and their balance researched,” says Karpeles, and one wallet was found to hold a balance of 199,999.99 bitcoins.
Karpeles says that the money, discovered on 7 March, was moved first to online wallets, and then back to an offline wallet between 14-15 March. After the discovery, Gox now holds around 202,000 bitcoins, and still says that approximately 650,000 bitcoins have “disappeared”.
MtGox closed doors in late February, after blaming hackers for the loss of millions of pounds worth of bitcoin. Since then, the firm’s US subsidiary has applied for bankruptcy, and two class action lawsuits have been started by users.
As every bitcoin transaction is public, it is possible to double-check MtGox’s claim. The rediscovered wallet appears to be one which was noticed on 7 March, when it sprung into life after a dormant period and transferred exactly 199,999.99 bitcoins in two separate transactions.
However, there remains a minor conflict between MtGox’s public statement and the evidence in the “block chain”, the record of all transactions. While Karpeles says “an” old-format wallet was discovered, the record shows that the money was spread between five wallets. The difference is minor, but in the highly charged reaction to MtGox’s closure, it is likely to be seized upon as evidence of untrustworthiness on the company’s part.
NiceHash also recommended that users change their online passwords as a precaution, though they added “the full scope of what happened is not yet known.”
NiceHash said it is working to determine the exact amount of Bitcoin that was stolen. However, the Wall Street Journal reported that Andrej P. Škraba, head of marketing at NiceHash, confirmed to the outlet that approximately 4,700 bitcoin, worth about $70 million, was missing from NiceHash’s bitcoin wallet. Škraba also told the Journal that “it was a professional attack,” but would not give any more information, noting that developments would be released at a later date.
NiceHash said its payment system was also compromised following the incident.
“We are fully committed to restoring the NiceHash service with the highest security measures at the earliest opportunity,” the cryptocurrency-mining service said in its post.
@nelson.madzima
