It is believed that The most recent attack of 51% that affected Ethereum Classic (ETC) resulted in a double issue of the cryptocurrency amounting to approximately $ 5.6 million.
A report published by Aleksey Studnev on August 5th on the blockchain startup Bitquery revealed the scope of the incident and estimated it The attacker took 807,260 FTEs.
The report estimates that the hacker made more than 2,800% profit for its efforts.After spending approximately $ 17.5 bitcoins (BTC) worth $ 192,000 to rent hash power from Nicehash to carry out the attack.
The report contradicts the original theories suggesting that the reorganization of the blockchain may not have been intentional.
The refined double editions
The attack took place between July 31st and August 1stHowever, due to the complicated planning and knowledge of the Ethereum Classic protocol, it was not recognized for several days. The hacker started the attack by transferring ETC from a wallet he controlled and then doing it again.
After renting the hash power from Nicehash provider ‘daggerhashimoto’ to take command of most of the hash power from Ethereum Classic, The attacker was able to mine 4,280 blocks in four days. The attacker then created private transactions that ETC would send to the wallets he controlled before issuing the blocks of transfers to his wallets to reorganize the blockchain.
More than 12 hours were spent executing transactions between the hacker-controlled exchanges and wallets along an unreorganized chainThis opened up the possibility of converting funds stolen from exchanges into a series of small operations to avoid detection.
It is believed that the hacker used OKEx’s address
In the incident, there were 11 malicious transactions that came from a single address embedded on the Ethereum blockchain more than 807,000 FTEs can be issued during the attack.
Bitquery believes that The wallet may be hosted by OKEx or one of the companies affiliated with the exchange, a suspicion that blockchain intelligence company Anchain also has.