The hackers who targeted the Harmony network in a $100 million attack last year have bridged their ill-gotten gains from the Bitcoin blockchain to the Avalanche, Tron and Ethereum platforms, according to on-chain analysis by blockchain sleuth MistTrack.

Lazarus Group, a North Korean hacking group that was behind the $635 million Ronin Bridge hack, is suspected to be behind the attack and subsequent transfers.

Last week, the hackers sent $63.5 million (41,000 ETH) to Railgun, a privacy-focused crypto wallet, before moving the funds on to various exchanges. The bitcoin (BTC) was then withdrawn from exchanges, with a portion of it being bridged to the Avalanche network.

In an attempt to further obfuscate the stolen funds, the hackers converted the bridged bitcoin for stablecoins tether (USDT) and USDD, which were subsequently sent to a multi-chain USDT address on both the Ethereum and Tron networks.

Hackers are being forced to go to extraordinary lengths to convert stolen crypto to fiat currency after the U.S. sanctioned popular coin mixing service Tornado Cash.

Blockchain security firm Chainalysis revealed that over $3 billion in crypto was lost across 125 hacks in 2022.