π¨ Minimalist USD ($USM) drained $136K
2026-08-09 |
#Ethereum
Attack Type: Flash-loan oracle / sliding-price manipulation
Attacker flash-loaned 11,580
$WETH from Balancer β spammed USM.defund() 65 times, burning the entire ~62M
$FUM position against the ETH pool.
Each defund call twisted the internal bidAskAdjustment (_defundFum β ls.bidAskAdjustment.wadMulDown), chunking the exit so the effective FUM sell price got inflated to ~$7.1M while the real oracle sat at ~$1,921.
Result: every burn extracted far more
$ETH than fair value. Loan repaid, net ~70.83 ETH profit straight out of the USM ETH reserve.
TX:
etherscan.io/tx/0xfae5e751b8β¦
Classic βmanipulate the adjustment curve, exit above markβ play. Another reminder that internal sliding prices + flash loans still print.