How much was lost in the CoinSWOP hack?

The CoinSWOP hack resulted in $21K in losses on December 04, 2020.

What attack technique was used in the CoinSWOP exploit?

The CoinSWOP 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.

CoinSWOP Hack

TOTAL LOST $21K

Low Dec 04, 2020 Rugpull ethereum

Affected Chain ethereum Incident surface

Recovered - No recovery reported

All-Time Rank #1881 By amount stolen

Protocol Type Token Locker Target category

Incident Overview

The contract owner invoked setMigrator() function at:

https://etherscan.io/tx/0xf73a10ee…9007f1

CoinSWOPMaster smart contract was set as migrator. The smart contract owner called migrate() functions 11 times to withdraw the user's LP tokens with the help of infinite approval. LP tokens were migrated to an unverified smart contract that received real LP tokens and returned fake ones. Then real LP tokens went to the contract deployer as the final recipient. Migrate transaction example:

https://etherscan.io/tx/0x5b19f1e3…48c592

The final recipient is getting LP tokens:

https://etherscan.io/tx/0xe6543f5b…3c5aea

LP tokens were exchanged for ETH and deposited to the Tornado Cash mixer at these transactions:

https://etherscan.io/tx/0xd6584b95…f8578c

https://etherscan.io/tx/0x90bd78b4…05b47c

https://etherscan.io/tx/0x5d530f23…08667d

6.8 ETH were transferred to some external wallet:

https://etherscan.io/tx/0xf8759517…b48867

Incident Report

Protocol / Project CoinSWOP

Date of Incident December 04, 2020

Affected Chain(s) ethereum

Attack Technique Rugpull

Classification CeFi

Primary Source View Post-Mortem

Protocol Information

Protocol Type Token Locker

Affected Token cSWOP

Official Website coinswop.org/

Protocol Twitter/X @Coin_Swop

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 ethereum smart contracts and deploy a custom exploit contract

Protocol Analysis Identification of the exploitable vulnerability in CoinSWOP's contract logic - root cause: cefi

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 CoinSWOP, these are the critical security checks that could have prevented this incident (December 2020).

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://twitter.com/CaptainJackAPE/status/1333759436792315905

Threat Assessment

Severity Level

LOW

Attack Vector Rugpull
Root Cause CeFi
Year 2020

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