Incident Overview
The attacker:
https://cchain.explorer.avax.network/address/0x9ed2D048…3Abf86/transactions
The transaction behind the attack:
https://cchain.explorer.avax.network/tx/0x8b3042e5…eb75ac/token-transfers
The hack was due to the lack of deflationary token support in the MasterChef contract. By repeated deposits and withdrawals with the MasterChef, the attacker frequently triggers the tax collection, which led to the exploit.
The attacker deployed the contract with the malicious logic at:
https://cchain.explorer.avax.network/tx/0x771c4454…65c319/internal-transactions
Further, he interacted with that contract to successfully pulled out 4.5 billion ZABU tokens in Zabu Farm Contract.
The list of stolen assets:
- WETH: 402.9
- WAVAX: 23,157
- PNG: 21,501
- AVE: 106,848
- USDT: 361,267
- JOE: 23,958.93
Incident Report
Protocol Information
Market Context at Time of Hack
What the Attacker Needed to Succeed
Understanding the prerequisites for this type of attack helps auditors identify protocols that are most at risk and helps developers build better defenses.
What Auditors Should Check
If you're auditing a protocol with similar architecture to Zabu Finance, these are the critical security checks that could have prevented this incident (September 2021).
- Verify all logic paths related to Flashloan Exploit / Other are guarded by proper access controls and input validation - see the Flash Loans Attacks attack class for patterns
- Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs
Master these auditing techniques with hands-on labs and real exploit scenarios in the Smart Contract Hacking course.
Free TrialRelated Attack Classes
The technique used in this hack maps to these vulnerability classes in our security curriculum:
Proof-of-Concept Exploits
On-Chain Evidence & References
Sources & References
Learn to Prevent the Next Zabu Finance
The Zabu Finance hack is one of many attacks that skilled auditors are trained to detect before deployment. Master real exploit patterns and defense techniques with hands-on Web3 security training.