The distributed denial-of-service (DDOS) attacks have hit a number of bitcoin mining pools and operations, including AntPool, BW.com, NiceHash, CKPool and GHash in recent days. The incidents are expected to have started earlier this month, with the attackers reportedly demanding payment in bitcoin in return for stopping the attacks.
BW.com cautioned its customers through its blog against possible service disruptions due to the attacks, however, it did not mention whether or not a ransom notice had been sent. Other pools approached Bitcoin Talk to alert users about the said attacks.
GHash operator CEX.io said that affected pools are witnessing rising DDOS threats.
"The attack has been conducted by a hacker who has already DDOSed in October, 2014. Previously, he demanded 2 BTC for stopping the attack. This time, the payment has been raised to 5 to 10 BTC", said a CEX spokesperson.
Operators while replying to press queries said that they have denied paying the ransoms and will keep their pools open regardless of the risk of future DDOS attacks.
Bitmain's Yoshi Goto pointed out that the attacks seem to be systematic and that it remains uncertain as to when the problem will be fully resolved.
"It is a cat and mouse game now but we will do our best," he said.
