Merlin Lab Performance Fee Minting Incident Analysis
Fool me once, shame on you. Fool me twice, shame on me. Fool me three times, shame on both of us.
Disclosures: Merlin Lab has engaged WatchPug to perform the 4th audit on their updated security code.
On May 26, 2021, 03:59:05 AM +UTC, less than 48 hrs after the Autoshark hack. Merlin Lab, well, another Bunny fork, been attacked in a similar fashion to the Bunny and the Autoshark hack.
As a result, the hacker has taken out 240 ETH (680K USD).
Check out the Transaction Details on BscScan.
- Added a small sum of deposit to the LINK-BNB Vault (with this transaction).
- Send 180 CAKE to the LINK-BNB Vault contract. (this is important! this is the key that leads to the hack.)
- Call getReward with the deposit of LINK-BNB Vault from the first step.
- With the rather large amount of CAKE token in the wallet balance of the vault contract (sent by the hacker at step 2), it returned a large amount of profit (see detailed analysis below). As a result, the system minted 100 MERLIN as a reward to the hacker.
- Repeated 36 times. Got 49K of MERLIN token in total.
- Swapped MERLIN token into 240 ETH and transferred out of BSC using Anyswap.
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