How much was lost in the Bing Swap hack?

The Bing Swap hack resulted in $10K in losses on April 03, 2021.

What attack technique was used in the Bing Swap exploit?

The Bing Swap 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.

Bing Swap Hack

TOTAL LOST $10K

Low Apr 03, 2021 Rugpull binance

Affected Chain binance Incident surface

Recovered - No recovery reported

All-Time Rank #1940 By amount stolen

Auditors 1 Prior security audit

Incident Overview

The project was holding a fundraising event using Bounce:

https://app.bounce.finance/fixed-swap/4710

The project raised 30.93 BNB in total. Liquidity wasn't added.

"We are in hacking attack and lost all of funds, so please be patient" in the announcement message:

https://archive.is/JnuJX

In addition, the project CEO's photo is fake. They used a real photo of the former prime minister of Ukraine, Yulia Timoshenko:

https://archive.is/1AWQP

Incident Report

Protocol / Project Bing Swap

Date of Incident April 03, 2021

Affected Chain(s) binance

Attack Technique Rugpull

Classification Yield Aggregator

Primary Source View Post-Mortem

Protocol Information

Protocol Type Dexs

Affected Token BING

Official Website bingswap.finance/

Protocol Twitter/X @BingSwap

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 binance smart contracts and deploy a custom exploit contract

Protocol Analysis Identification of the exploitable vulnerability in Bing Swap's contract logic - root cause: yield aggregator

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

Audited by Audit Report 1 — still lost $10K. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to Bing Swap, these are the critical security checks that could have prevented this incident (April 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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Security Audit History

Audit Report 1 Report

Sources & References

01
Source 1 https://twitter.com/DisNagger/status/1369471049423876098
02
Web Archive https://web.archive.org/web/20210308074929/https://bingswap.finance/

Threat Assessment

Severity Level

LOW

Attack Vector Rugpull
Root Cause Yield Aggregator
Year 2021

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