Ethereum Classic Suffers Another 51% Attack
- Hackers siphoned $5.6 million in crypto in a similar attack last week.

Ethereum Classic has suffered another 51 percent attack this morning, resulting in the reorganization of over 4,000 blocks.
The attacker can reorganize the chains on a decentralized network when they gain over 51 percent of the total Hash Rate Hash Rate A hash rate is the measure of a cryptocurrency miner’s performance and a key security metric. In the context of mining, the more hashing or computing power in a given network, the greater its security and its overall resistance to attackMining hashrate is a key security metric. The more hashing (computing) power in the network, the greater its security and its overall resistance to attack. Hash rate is also a measurement of the output of a device that is used to add transactions to a blockchain A hash rate is the measure of a cryptocurrency miner’s performance and a key security metric. In the context of mining, the more hashing or computing power in a given network, the greater its security and its overall resistance to attackMining hashrate is a key security metric. The more hashing (computing) power in the network, the greater its security and its overall resistance to attack. Hash rate is also a measurement of the output of a device that is used to add transactions to a blockchain Read this Term. This can result in rewriting the chain history or even double-spending.
The recent attack on the network was revealed by mining pool operator, Bitfly, and crypto exchange, Binance, the first has halted all Ethereum Classic payouts for mining, while the exchange has suspended ETC withdrawals and deposits.
A new chain reorg of 4,000+ blocks has occurred on @eth_classic $ETC at block 10935622.
Our alert system caught this immediately and automatically halted withdrawals and deposits. It appears to be a follow up 51% attack. We will update you as things unfold. — Binance (@binance) August 6, 2020
The developers of the cryptocurrency also urged the community to raise the confirmation time of any transaction involving Ethereum Classic following the attack.
In light of recent network attacks, it's recommended that all exchanges, mining pools, and other ETC service providers significantly raise confirmation times on all deposits and incoming transactions. @okex @binance @HuobiGlobal @hitbtc @coinbase @digifinex @etherchain_org
— Ethereum Classic (@eth_classic) August 6, 2020
The reorganized blocks have become the longest chain on the network, and the miners are now mining the other shorter version. Hash rate on the Ethereum Classic network has also dropped by around 20 percent since the beginning of the week.
A Vulnerable Blockchain Blockchain Blockchain comprises a digital network of blocks with a comprehensive ledger of transactions made in a cryptocurrency such as Bitcoin or other altcoins.One of the signature features of blockchain is that it is maintained across more than one computer. The ledger can be public or private (permissioned.) In this sense, blockchain is immune to the manipulation of data making it not only open but verifiable. Because a blockchain is stored across a network of computers, it is very difficult to tampe Blockchain comprises a digital network of blocks with a comprehensive ledger of transactions made in a cryptocurrency such as Bitcoin or other altcoins.One of the signature features of blockchain is that it is maintained across more than one computer. The ledger can be public or private (permissioned.) In this sense, blockchain is immune to the manipulation of data making it not only open but verifiable. Because a blockchain is stored across a network of computers, it is very difficult to tampe Read this Term
Notably, the fresh attack followed similar attacks on the Etheruem Classic blockchain between July 29 and August 1.
An analysis published on Wednesday by blockchain intelligence firm Bitquery detailed that the attacker paid around 17.5 BTC to gain 51 percent hash rate of the blockchain and double-spent over 800,000 ETC, valued around $5.6 million.
The details of this morning’s attack, however, is not yet known, meaning it is unclear how much the attacker spent and how many cryptos were double-spent. However, the attacker might have received $93,760 from blockchain mining rewards alone, given the $23.44 per block reward for Ethereum Classic mining.
Despite the attacks, the market value of the cryptocurrency did not take a hit as it is being traded sideways without any significant swing.
Ethereum Classic has suffered another 51 percent attack this morning, resulting in the reorganization of over 4,000 blocks.
The attacker can reorganize the chains on a decentralized network when they gain over 51 percent of the total Hash Rate Hash Rate A hash rate is the measure of a cryptocurrency miner’s performance and a key security metric. In the context of mining, the more hashing or computing power in a given network, the greater its security and its overall resistance to attackMining hashrate is a key security metric. The more hashing (computing) power in the network, the greater its security and its overall resistance to attack. Hash rate is also a measurement of the output of a device that is used to add transactions to a blockchain A hash rate is the measure of a cryptocurrency miner’s performance and a key security metric. In the context of mining, the more hashing or computing power in a given network, the greater its security and its overall resistance to attackMining hashrate is a key security metric. The more hashing (computing) power in the network, the greater its security and its overall resistance to attack. Hash rate is also a measurement of the output of a device that is used to add transactions to a blockchain Read this Term. This can result in rewriting the chain history or even double-spending.
The recent attack on the network was revealed by mining pool operator, Bitfly, and crypto exchange, Binance, the first has halted all Ethereum Classic payouts for mining, while the exchange has suspended ETC withdrawals and deposits.
A new chain reorg of 4,000+ blocks has occurred on @eth_classic $ETC at block 10935622.
Our alert system caught this immediately and automatically halted withdrawals and deposits. It appears to be a follow up 51% attack. We will update you as things unfold. — Binance (@binance) August 6, 2020
The developers of the cryptocurrency also urged the community to raise the confirmation time of any transaction involving Ethereum Classic following the attack.
In light of recent network attacks, it's recommended that all exchanges, mining pools, and other ETC service providers significantly raise confirmation times on all deposits and incoming transactions. @okex @binance @HuobiGlobal @hitbtc @coinbase @digifinex @etherchain_org
— Ethereum Classic (@eth_classic) August 6, 2020
The reorganized blocks have become the longest chain on the network, and the miners are now mining the other shorter version. Hash rate on the Ethereum Classic network has also dropped by around 20 percent since the beginning of the week.
A Vulnerable Blockchain Blockchain Blockchain comprises a digital network of blocks with a comprehensive ledger of transactions made in a cryptocurrency such as Bitcoin or other altcoins.One of the signature features of blockchain is that it is maintained across more than one computer. The ledger can be public or private (permissioned.) In this sense, blockchain is immune to the manipulation of data making it not only open but verifiable. Because a blockchain is stored across a network of computers, it is very difficult to tampe Blockchain comprises a digital network of blocks with a comprehensive ledger of transactions made in a cryptocurrency such as Bitcoin or other altcoins.One of the signature features of blockchain is that it is maintained across more than one computer. The ledger can be public or private (permissioned.) In this sense, blockchain is immune to the manipulation of data making it not only open but verifiable. Because a blockchain is stored across a network of computers, it is very difficult to tampe Read this Term
Notably, the fresh attack followed similar attacks on the Etheruem Classic blockchain between July 29 and August 1.
An analysis published on Wednesday by blockchain intelligence firm Bitquery detailed that the attacker paid around 17.5 BTC to gain 51 percent hash rate of the blockchain and double-spent over 800,000 ETC, valued around $5.6 million.
The details of this morning’s attack, however, is not yet known, meaning it is unclear how much the attacker spent and how many cryptos were double-spent. However, the attacker might have received $93,760 from blockchain mining rewards alone, given the $23.44 per block reward for Ethereum Classic mining.
Despite the attacks, the market value of the cryptocurrency did not take a hit as it is being traded sideways without any significant swing.