The Yearn protocol yETH pool was attacked, resulting in a loss of nearly 9 million dollars, with the Hacker using a custom contract to mint coins wildly.

[Chain News] The Yearn protocol had an incident last night. On November 30th at 9:11 PM UTC (, their yETH stable pool was hacked.

The attacker pulled a crazy move—using a custom contract to mint yETH tokens like crazy. This directly caused about 8 million dollars in the pool to go down the drain, and the yETH-WETH liquidity pool on Curve also suffered, losing about 900,000 dollars. In total, it’s nearly a 9 million dollar hole.

However, Yearn's official team quickly came out to reassure everyone: the code that was affected this time is independent, and the V2 and V3 versions of the vaults )Vaults( are fine, and other products are safe as well. They stated that the complexity of this attack is similar to the previous incident with Balancer — it seems that the hackers indeed put in a lot of effort.

The team has now contacted SEAL911 and their old partner audit company ChainSecurity, and the parties are conducting a joint investigation into this matter. A more detailed technical analysis report should be released later.

The security issues in DeFi have sounded the alarm again; these days, it's really hard to guard against the pitfalls of smart contracts.