How much was lost in the HECO hack?

The HECO hack resulted in $86.3M in losses on November 22, 2023.

What attack technique was used in the HECO exploit?

The HECO 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.

HECO Hack

TOTAL LOST $86.3M

High #88 All-Time Nov 22, 2023 Access Control

Affected Chain 2023 Incident surface

Recovered - No recovery reported

All-Time Rank #88 By amount stolen

Protocol Type Exploit/Access control Target category

Incident Overview

Quick Summary

Heco Bridge suffered an access control exploit on Nov 22, 2023, resulting in a loss of over 86,284,430 USD worth of various assets.

Details of the Exploit

Heco Bridge, a cross-chain bridge between Ethereum and Heco chain, fell victim to an access control exploit on Nov 22, 2023. The exploit led to the loss of 86,284,430 USD worth of assets, including 10,145 ETH, 42,110,000 USDT, 489 HBTC, 346,867,120,000 SHIB, 173,200 UNI, 619,000 USDC, 42,399 LINK, and 346,994 TUSD. The private keys of a privileged address were compromised, allowing the attacker to withdraw funds from the bridge's smart contract.

The stolen funds were transferred to the hacker's main address in several transactions and swapped for ETH in DEXes using multiple EOA addresses. The native ETH was then accumulated in another EOA and distributed among five addresses, where the funds remain as of Nov 23, 2023.

Block Data Reference

Attacker Address:

https://etherscan.io/address/0xfc146d1c…50b0c4

Malicious Transactions:

https://etherscan.io/tx/0xbb6fe884…3e131b

https://etherscan.io/tx/0x46f2ebab…57b1e8

https://etherscan.io/tx/0x98b44a9d…b5a375

Funds Transfer Transactions:

https://etherscan.io/tx/0xe021e1d8…3b2d87

https://etherscan.io/tx/0x793a8f4c…c5766b

Funds Holders as of Nov 23, 2023:

https://etherscan.io/address/0xe47e6dA1…089B9e

https://etherscan.io/address/0xedbdcb1b…18b8f6

https://etherscan.io/address/0x7befdbb8…552935

https://etherscan.io/address/0x8dc70e03…b9ab75

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

Incident Report

Protocol / Project HECO

Date of Incident November 22, 2023

Attack Technique Access Control

Classification Bridge

Primary Source View Post-Mortem #1 View Post-Mortem #2

Protocol Information

Protocol Type Exploit/Access control

Protocol Twitter/X @HECO_Chain

Team Public / Doxxed

Source Code Verified On-Chain

Market Context at Time of Hack

Token Categories

BNB Chain Ecosystem

Protocol Links

GitHub Reddit Telegram Website

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 HECO'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 HECO, these are the critical security checks that could have prevented this incident (November 2023).

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/justinsuntron/status/1727304656622326180
02
Source 2 https://twitter.com/PeckShieldAlert/status/1727286692489679360?s=20

Threat Assessment

Severity Level

HIGH

Attack Vector Access Control
Root Cause Bridge
Year 2023

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