Worked example · 2022-04

Beanstalk Farms flash-loan governance attack — Ethereum — 2022-04-17

Loss

about $181M gross, of which the attacker kept about $76M (about 24,830 WETH) [rektbeanstalk]. The Beanstalk team's post-mortem puts the stolen non-Beanstalk user assets at about $77M [beanpostmortem].

OAK Techniques observed

OAK-T16.001 (Flash-Loan Governance Vote Manipulation — primary; flash-loaned funds were used to gain voting power and execute a malicious proposal [rektbeanstalk]). OAK-T9.002 (Flash-Loan-Funded Attack — Aave, Uniswap v2 and SushiSwap loans [rektbeanstalk]). OAK-T9.003 (Governance Attack). OAK-T7.001 (Mixer-Routed Hop — about 24,800 ETH went to Tornado Cash [rektbeanstalk]). OAK-T6.001 (original mapping for the Ukraine-donation proposal; see correction below).

Attribution

pseudonymous attacker; no individual is named by the cited sources. Rekt notes the exploiter was initially funded from Tornado Cash and the Synapse bridge [rektbeanstalk].

Corrected 2026-10-11

the exploit was not a single transaction creating and passing a proposal — two proposals were submitted the day before and executed through an emergency path; the loan sources were Aave, Uniswap v2 and SushiSwap; the Ukraine donation was about $250K sent to a donation address (a separate proposal mislabelled "Bip18"), not the drain's stated purpose; removed the unsourced Curve-LP balanceOf governance description, "~70%" weight, "$106M fees", the attacker address, timeline hours and relaunch details.

Key teaching point

Governance that lets freshly borrowed capital count as voting power, combined with an emergency execution path that skips the usual delay, lets an attacker take a treasury in one sitting. Rekt: all governance actions had about a one-day delay, but the malicious proposal was executed via an emergency path with no delay [rektbeanstalk].