On March 13, 2023, Euler Finance, a permissionless borrowing and lending protocol on Ethereum, was the victim of a flash loan attack. In this blog, we’ll explore how flash loans work, how hackers stole funds from Euler Finance, and how the effects of flash loan attacks may be mitigated in the future. What is a flash loan? Before analyzing the details of the Euler hack, it is important to understand how flash loans typically work. How the Euler Finance flash loan attack occurredWhen users borrow and lend using the Euler Finance platform, they primarily transact with two types of tokens: eTokens (which represent collateral) and dTokens (which represent debt).