A non-fungible token (NFT) auction on the MISO token launchpad built on the SushiSwap platform appears to have been hacked, with the attacker making off with roughly $3 million in ether, SushiSwap Chief Technology Officer Joseph Delong tweeted Thursday.

Delong said that an anonymous contractor using the Github handle “AristoK3″ injected malicious code into Miso’s front end in a supply chain attack. He added the link to an Ethereum address showing ETH 864.8 transferred at approximately 16:00 UTC on Thursday.Etherscan has identified the address as part of an exploit.Supply chain attacks happen when a malicious actor changes a contract address to one they control. That type of attack can occur with open-source software libraries, according to the U.S. National Counterintelligence and Security Center.Only one contract appears to have been exploited, according to Delong, for the JayPegsAutoMart NFT sale.The attacker, who has done work with decentralized finance (DeFi) protocol yearn.finance, replaced the auction’s wallet address with their own, Delong said.Delong said SushiSwap “has reason to believe” the attacker was eratos1122, linking to a Twitter account that identifies as a blockchain and mobile games developer.SushiSwap has asked crypto exchanges FTX and Binance, to hand over the hacker’s know-your-customer information of the individual.CoinDesk hasn’t been able to independently verify the attacker’s identity as of press time.If the funds are not returned by 12:00 UTC, the DeFi exchange will file a complaint with the FBI, Delong said.