Malicious Uniswap v4 Hooks Bait Traders with Fake Swap Quotes

A new threat has emerged in the DeFi space as malicious Uniswap v4 hooks have been baiting traders with fake swap quotes, according to a report by Liquidity aggregator 0x. The company found that 19.4% of Uniswap v4 hooks it examined were safe, while 54.2% were malicious and 26.4% likely malicious.

The malicious hooks are designed to quote one price and settle at another, with some extreme trades resulting in users receiving as much as 50% less than the displayed quote. The report notes that Uniswap v4 hooks are optional external contracts that can run around key pool actions, and while they offer flexibility, they also enable malicious behavior.

0x has observed that malicious routes deliver up to half less than quoted, with one hook trading the ETH/NVDAc pair collecting $143,037 in total fees as of September 11. The company routes 81.92 million trades and $42.67 billion in volume through Uniswap liquidity, making it a significant player in the DeFi market.