1 Quadrillion yUSDT Minted in Yearn Finance Exploit: What Happened?

• PeckShield detected an exploit on the lending platform Yearn Finance which resulted in 1 quadrillion Yearn Tether (yUSDT) being minted.
• The hacker swapped the yUSDT to other stablecoins and transferred 1,000 Ether to Tornado Cash.
• The price of yearn.finance (YFI) token dipped after the news was made public but has since recovered.

Exploit Detected on Yearn Finance

Blockchain Security firm PeckShield recently detected an exploit on the lending platform Yearn Finance that resulted in an irregular minting of over 1 quadrillion Yearn Tether (yUSDT) using $10,000.

Hacker’s Activity

The hacker proceeded to swap the yUSDT to other cryptocurrencies including $11.6 million worth of stablecoins such as Binance USD (BUSD), TrueUSD (TUSD), Tether (USDT), USD Coin (USDC), DAI, and Pax Dollar (USDP). In addition, the hacker also managed to transfer 1,000 Ether worth about $2 million to the sanctioned crypto mixer Tornado Cash.

Yearn Finance Statement

Yearn Finance made a statement after initial checks and stated that the hack was limited to an outdated smart contract before versions V1 and V2 called iearn. Furthermore, they assured that current Yearn Finance contracts and protocols were not affected by the exploit. Aave also confirmed they were aware of this hack but none of their versions (V1, V2, and V3) were affected by it either.

Impact on Price

The price of yearn.finance (YFI) token dipped to about $8,945 immediately after news about the hack broke out but has since recovered to $9,094 at press time. Although still lower than yesterday’s trading level by 2%, it is still higher than 7% compared to its value over last seven days prior to this incident.


To conclude, blockchain security firm PeckShield detected an exploit on lending platform Yearn finance which resulted in irregular minting of 1 quadrillion yUSDT tokens using $10k only while hacker transferred 1000 ETH worth around $ 2 million into crypto mixer Tornado Cash too during same event & price dip down shortly but regained quickly again!