The hacker responsible for last year’s Poloniex hack has transferred 1,100 ETH, valued at around $3.4 million, to the U.S.-sanctioned cryptocurrency mixer Tornado Cash in an attempt to launder the stolen funds, according to on-chain data from security firm PeckShield.

Poloniex was drained of $100 million during an attack on one of its hot wallets in November last year. Mixing services like Tornado Cash are often used by cybercriminals to obfuscate the trail of stolen cryptocurrency.

This attack is widely considered to be the work of the North Korean Lazarus Group, a notorious state-sponsored hacking organization that has previously executed high-profile attacks, including a $600 million hack on the Ronin sidechain.

In a previous on-chain message, Poloniex offered the attacker a 5% …