Ethereum Classic (ETC) is reportedly under 51% Attack.
According to the statement on the Coinbase blog,
“On 1/5/2019, Coinbase detected a deep chain reorganization of the Ethereum Classic blockchain that included a double spend”.
In order to protect customer funds, Coinbase “immediately paused interactions with the ETC blockchain”. Subsequently, they detected 12 additional reorganizations that included double spends, totalling 219,500 ETC (~$1.1M).
Coinbase further explained:
“The miner could send those coins to a merchant in a transaction, T, while also secretly extending an alternative block history. The miner’s secret blocks do not include T, but rather include a transaction that sends the same coins used in T to a different address.”
Denying the allegations, ETC replied through the following tweet: