Ethereum Classic

51% Attack on Ethereum Classic at the start of the year 2019

Ethereum Classic had gone through a 51% attack which amounted to around 54,200 ETC being traded and rolled back. Ethereum Classic is one of the top 20 cryptocurrencies out there based on Market Cap. According to their website:

Ethereum Classic (ETC) is a smarter blockchain, it is a network, a community, and a cryptocurrency that takes digital assets further. In addition to allowing people to send value to each other, ETC allows for complex contracts that operate autonomously and cannot be modified or censored.

But still, like all Proof Of Work Crypto out there, each crypto including even the Big Brother, Bitcoin is also susceptible to 51% Attack. A 51% Attack is a type of attack, where a single/group of people with same motive having at least 51% of the network hashrate, attacks the network for their cause.

The above though looked like a bad factor, is a validation that it is decentralised. As said by Charlie Lee:

“By definition, a decentralized cryptocurrency must be susceptible to 51% attacks whether by hashrate, stake, and/or other permissionlessly-acquirable resources. If a crypto can’t be 51% attacked, it is permissioned and centralized.”

And that is what recently happened to Ethereum Classic. Research confirmed the 51% attack on ETC. In the analysis, detected 7 rollback transactions. The attacker created four of them, transferring a total of 54,200 ETC. The txhash of the for transactions are


It happened between 0:40 Jan.7, 2019 and Jan 4:20 Jan.7, 2019 UTC for about 4 hours. All the transactions were confirmed usually on the ETC blockchain and became invalid after the blockchain rollback. Three of the attacker’s ETC accounts are identified as follows:


Due to the recent events, has raised the ETC confirmation number to 500 and launched a new strict 51% detect for enhanced protection. It has also mentioned that: will take all the loss for the users.

The SlowMist team has done a detailed analysis of the same.

Update: 12 January 2019 got back 100k USD Value Of ETC from the ETC 51% Attacker as per a report posted on their own blog. They also reminded the public that: “If the attacker didn’t run it for profit, he might be a white (hat) hacker who wanted to remind people (of) the risks in blockchain consensus and hashing power security

Published by Shebin John

An engineer by Profession, Marketer by Choice and Investor by Passion. Computer Science Engineer who loves to spend time learning new things, technologies, and frameworks.