On June 12, Chinese media outlet Chainnews reported that analyst firm PeckShield concluded that the millions of dollars in fee chain was paid by hackers seeking to redeem a cryptocurrency exchange.
The report speculates that the exchange was compromised during a phishing attack, allowing hackers to gain control over many of the platform’s operating rights, including its servers.
Researchers believe the hackers are threatening to empty the exchange wallets, if they are not paid for bribes, with PeakShield claiming that 21,000 ETH is still in the wallet under the hacker’s control.
Seems the victim has been found. It was Korean exchange which appears markedly smaller than initially being thought. It lacks security and is been suspected into Ponzi scheme involvement, and therefore, owners didn't file a claim about the hack. All the fee went to miners: https://decrypt.co/32604/heres-who-paid-5-2-million-in-ethereum-fees-last-week Happy end?