How much was lost in the ChocSwap.finance hack?

The ChocSwap.finance hack resulted in — in losses on September 30, 2021.

What attack technique was used in the ChocSwap.finance exploit?

The ChocSwap.finance exploit utilized Rugpull. 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.

ChocSwap.finance Hack

TOTAL LOST —

Sep 30, 2021 Rugpull

Affected Chain 2021 Incident surface

Recovered - No recovery reported

Same Technique 865 Total incidents

Protocol Type Dexs Target category

Incident Overview

Easy and fast trade-in EOS EVM

Incident Report

Protocol / Project ChocSwap.finance

Date of Incident September 30, 2021

Attack Technique Rugpull

Classification Exchange (DEX)

Primary Source View Post-Mortem

Protocol Information

Protocol Type Dexs

Affected Token CHOC

Official Website chocswap.finance

Protocol Twitter/X @EoswapFinance

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 Deep understanding of rugpull and Solidity and EVM internals

Capital Required Seed capital to cover gas and initial position setup

On-Chain Access Ability to interact with smart contracts and deploy a custom exploit contract

Protocol Analysis Identification of the exploitable vulnerability in ChocSwap.finance's contract logic - root cause: exchange (dex)

Execution Speed Precise transaction ordering and timing to exploit the vulnerability within a single atomic block

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? Hard to catch — private key / OpSec failures are outside smart contract audit scope

If you're auditing a protocol with similar architecture to ChocSwap.finance, these are the critical security checks that could have prevented this incident (September 2021).

Verify all logic paths related to Rugpull are guarded by proper access controls and input validation
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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Sources & References

01
Source 1 https://bscscan.com/token/0x9da9dc22c7b7d1d38a01ee074ed46a8e10e1…

Threat Assessment

Severity Level

UNKNOWN

Attack Vector Rugpull
Root Cause Exchange (DEX)
Year 2021

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