How much was lost in the Jeffrey Zirlin hack?

The Jeffrey Zirlin hack resulted in $9.7M in losses on February 22, 2024.

What attack technique was used in the Jeffrey Zirlin exploit?

The Jeffrey Zirlin exploit utilized Access Control. Understanding this attack vector is critical for smart contract auditors and developers building secure DeFi protocols.

How can developers prevent similar smart contract attacks?

Preventing smart contract hacks requires a combination of secure coding practices, thorough security audits, and understanding common attack vectors like reentrancy, oracle manipulation, and access control flaws. Smart Contract Hacking (SCH) provides hands-on training to help developers and auditors identify and prevent vulnerabilities before deployment.

Jeffrey Zirlin Hack

TOTAL LOST $9.7M

Medium Feb 22, 2024 Access Control

Affected Chain 2024 Incident surface

Recovered - No recovery reported

All-Time Rank #314 By amount stolen

Protocol Type Exploit/Access control Target category

Incident Overview

Quick Summary

Jeffrey Zirlin "Jihoz", Axie Infinity co-founder, experienced a private key compromise, resulting in a loss of approximately 9,700,000 USD.

Details of the Exploit

On February 23, 2024, Jihoz_Axie tweeted on his X (formerly twitter) about compromise of his two personal wallet addresses,. The attacker stole assets from these wallets, swapped them to Ronin WETH, and bridged them to the Ethereum mainnet using Axie Infinity:Ronin Bridge. The stolen funds were then transferred to other EOA addresses and eventually deposited into TornadoCash through several addresses.

Block Data Reference

Attacker Address:

https://ronin.bloks.io/address/0x39f81797…713105

Additional Attacker's Addresses:

https://etherscan.io/address/0xA4017DE6…eD13b2

https://etherscan.io/address/0x73f428e1…dEC8B8

Malicious Transactions:

https://ronin.bloks.io/transaction/0xe5fcb3ea…937003

https://ronin.bloks.io/transaction/0x002e0c22…a68d1f

https://ronin.bloks.io/transaction/0x87841c81…27830e

TornadoCash Deposit Transactions:

https://etherscan.io/tx/0xeb112a22…669ab9

https://etherscan.io/tx/0x24055d9a…a1a5c7

This is classified as a Access Control Attacks . Compare similar hacks →

Incident Report

Protocol / Project Jeffrey Zirlin

Date of Incident February 22, 2024

Attack Technique Access Control

Classification Other

Primary Source View Post-Mortem

Protocol Information

Protocol Type Exploit/Access control

Protocol Twitter/X @Jihoz_Axie

Team Anonymous

Source Code Unverified

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.

Technical Knowledge Operational-security tradecraft (phishing, malware, leaked seed phrases, or insider access) to obtain treasury signing authority

Capital Required Minimal capital - only enough to cover gas while draining the compromised accounts

On-Chain Access Valid signing authority over the compromised wallets / multisig signers, allowing direct transfer of funds or stake authorization

Target Reconnaissance Identification of Jeffrey Zirlin's high-value treasury accounts and the authority / multisig structure controlling them

Execution Speed Speed to drain the compromised accounts before the team detects the breach and revokes signing authority or freezes the assets

Obfuscation Plan A strategy to launder and move stolen funds - typically through mixers, cross-chain bridges, or decentralized DEX swaps to resist tracing

What Auditors Should Check

Could this have been caught in audit? Likely — with a thorough Access Control audit checklist and test coverage

If you're auditing a protocol with similar architecture to Jeffrey Zirlin, these are the critical security checks that could have prevented this incident (February 2024).

Verify all logic paths related to Access Control are guarded by proper access controls and input validation - see the Access Control 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.

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Related Attack Classes

The technique used in this hack maps to these vulnerability classes in our security curriculum:

See all Access Control Attacks examples →

Access Control Attacks

Sources & References

01
Source 1 https://twitter.com/Jihoz_Axie/status/1760845078757511562

Threat Assessment

Severity Level

MEDIUM

Attack Vector Access Control
Root Cause Other
Year 2024

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