AntPool, BW.com, NiceHash, CKPool and GHash.io are among a number of bitcoin mining pools and operations that have been hit by distributed denial-of-service (DDOS) attacks in recent days.
According to many of the companies affected by the incidents, those behind the attacks demanded payment in bitcoin in return for stopping the attacks.
operator CEX.io suggested that affected pools are seeing escalating DDOS threats, and said that the source of recent attacks on its pool came with increasing ransom demands.
A spokesperson for CEX.io told CoinDesk:
At least one other mining pool, NiceHash, also reported sustained DDOS attacks last fall.
The alleged source of the DDOS attacks, operating under the name DD4BC, is believed to be behind a number of attacks on digital currency websites and services in the past year.
Incidents tied to DD4BC include an attack last year on the digital currency exchange Bitalo that resulted in the posting of a 100 BTC bounty. Following the recent DDOS threats, Bitmain contributed an additional 10 BTC to the bounty.
Disruptions likely to continue
Affected pools say they have moved to boost in-house defense mechanisms in light of the attacks, but some have warned that future outages may likely occur. Bitmain said that its other services, including the cloud mining platform HashNest, may also be affected in the coming days.
Operators that responded to press queries say they have refused to pay the ransoms and will continue keeping their pools open despite the risk of future DDOS attacks.
Some of the pools have conceded that resolving the situation will be difficult owing to the capabilities believed to be possessed by the source of the attacks.
Bitmain’s Yoshi Goto noted that the attacks appear to be systematic and acknowledged that it remains unclear when the situation will be completely resolved.
“It is a cat and mouse game now but we will do our best,” he said.
CoinDesk will continue monitoring the developments and post updates as they become available.
The leader in news and information on cryptocurrency, digital assets and the future of money, CoinDesk is a media outlet that strives for the highest journalistic standards and abides by a strict set of editorial policies. CoinDesk is an independent operating subsidiary of Digital Currency Group, which invests in cryptocurrencies and blockchain startups. As part of their compensation, certain CoinDesk employees, including editorial employees, may receive exposure to DCG equity in the form of stock appreciation rights, which vest over a multi-year period. CoinDesk journalists are not allowed to purchase stock outright in DCG.