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 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 tamper with. The Evolution of BlockchainBlockchain was originally invented by an individual or group of people under the name of Satoshi Nakamoto in 2008. The purpose of blockchain was originally to serve as the public transaction ledger of Bitcoin, the world’s first cryptocurrency.In particular, bundles of transaction data, called “blocks”, are added to the ledger in a chronological fashion, forming a “chain.” These blocks include things like date, time, dollar amount, and (in some cases) the public addresses of the sender and the receiver.The computers responsible for upholding a blockchain network are called “nodes.” These nodes carry out the duties necessary to confirm the transactions and add them to the ledger. In exchange for their work, the nodes receive rewards in the form of crypto tokens.By storing data via a peer-to-peer network (P2P), blockchain controls for a wide range of risks that are traditionally inherent with data being held centrally.Of note, P2P blockchain networks lack centralized points of vulnerability. Consequently, hackers cannot exploit these networks via normalized means nor does the network possess a central failure point.In order to hack or alter a blockchain’s ledger, more than half of the nodes must be compromised. Looking ahead, blockchain technology is an area of extensive research across multiple industries, including financial services and payments, among others. 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 tamper with. The Evolution of BlockchainBlockchain was originally invented by an individual or group of people under the name of Satoshi Nakamoto in 2008. The purpose of blockchain was originally to serve as the public transaction ledger of Bitcoin, the world’s first cryptocurrency.In particular, bundles of transaction data, called “blocks”, are added to the ledger in a chronological fashion, forming a “chain.” These blocks include things like date, time, dollar amount, and (in some cases) the public addresses of the sender and the receiver.The computers responsible for upholding a blockchain network are called “nodes.” These nodes carry out the duties necessary to confirm the transactions and add them to the ledger. In exchange for their work, the nodes receive rewards in the form of crypto tokens.By storing data via a peer-to-peer network (P2P), blockchain controls for a wide range of risks that are traditionally inherent with data being held centrally.Of note, P2P blockchain networks lack centralized points of vulnerability. Consequently, hackers cannot exploit these networks via normalized means nor does the network possess a central failure point.In order to hack or alter a blockchain’s ledger, more than half of the nodes must be compromised. Looking ahead, blockchain technology is an area of extensive research across multiple industries, including financial services and payments, among others. 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 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 tamper with. The Evolution of BlockchainBlockchain was originally invented by an individual or group of people under the name of Satoshi Nakamoto in 2008. The purpose of blockchain was originally to serve as the public transaction ledger of Bitcoin, the world’s first cryptocurrency.In particular, bundles of transaction data, called “blocks”, are added to the ledger in a chronological fashion, forming a “chain.” These blocks include things like date, time, dollar amount, and (in some cases) the public addresses of the sender and the receiver.The computers responsible for upholding a blockchain network are called “nodes.” These nodes carry out the duties necessary to confirm the transactions and add them to the ledger. In exchange for their work, the nodes receive rewards in the form of crypto tokens.By storing data via a peer-to-peer network (P2P), blockchain controls for a wide range of risks that are traditionally inherent with data being held centrally.Of note, P2P blockchain networks lack centralized points of vulnerability. Consequently, hackers cannot exploit these networks via normalized means nor does the network possess a central failure point.In order to hack or alter a blockchain’s ledger, more than half of the nodes must be compromised. Looking ahead, blockchain technology is an area of extensive research across multiple industries, including financial services and payments, among others. 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 tamper with. The Evolution of BlockchainBlockchain was originally invented by an individual or group of people under the name of Satoshi Nakamoto in 2008. The purpose of blockchain was originally to serve as the public transaction ledger of Bitcoin, the world’s first cryptocurrency.In particular, bundles of transaction data, called “blocks”, are added to the ledger in a chronological fashion, forming a “chain.” These blocks include things like date, time, dollar amount, and (in some cases) the public addresses of the sender and the receiver.The computers responsible for upholding a blockchain network are called “nodes.” These nodes carry out the duties necessary to confirm the transactions and add them to the ledger. In exchange for their work, the nodes receive rewards in the form of crypto tokens.By storing data via a peer-to-peer network (P2P), blockchain controls for a wide range of risks that are traditionally inherent with data being held centrally.Of note, P2P blockchain networks lack centralized points of vulnerability. Consequently, hackers cannot exploit these networks via normalized means nor does the network possess a central failure point.In order to hack or alter a blockchain’s ledger, more than half of the nodes must be compromised. Looking ahead, blockchain technology is an area of extensive research across multiple industries, including financial services and payments, among others. 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.