How much was lost in the Zap Finance hack?

The Zap Finance hack resulted in $22K in losses on January 30, 2021.

What attack technique was used in the Zap Finance exploit?

The Zap 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.

Zap Finance Hack

TOTAL LOST $22K

Low Jan 30, 2021 Rugpull binance

Affected Chain binance Incident surface

Recovered - No recovery reported

All-Time Rank #1874 By amount stolen

Auditors 1 Prior security audit

Incident Overview

The contract deployer migrated the users' LP tokens by invoking depositReward() function at:

https://bscscan.com/tx/0xad5c9ab2…e6dde4

https://bscscan.com/tx/0x82189550…44a605

The liquidity was removed by the contract deployer at:

https://bscscan.com/tx/0x50bfb244…3a6b99

https://bscscan.com/tx/0xc00da145…ef3b48

https://bscscan.com/tx/0x2c5f46d7…3354b9

Stolen funds were transferred to the external wallet at:

https://bscscan.com/tx/0x887fd639…594eb5

https://bscscan.com/tx/0x0fabdcb1…450ff1

The recipient deposited funds into Binance Hot Wallet at:

https://bscscan.com/tx/0x1e9cac7e…cea409

https://bscscan.com/tx/0x08f6fbb2…79e7a6

Incident Report

Protocol / Project Zap Finance

Date of Incident January 30, 2021

Affected Chain(s) binance

Attack Technique Rugpull

Classification Exchange (DEX)

Primary Source View Post-Mortem

Protocol Information

Protocol Type Yield

Affected Token ZAP

Official Website zap.finance/

Protocol Twitter/X @apyfinance

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 Zap 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

Audited by Audit Report 1 — still lost $22K. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to Zap Finance, these are the critical security checks that could have prevented this incident (January 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://www.bsc.news/post/liquidity-siphon-rugpulls-on-the-binan…
02
Web Archive https://web.archive.org/web/20210128190627/https://zap.finance/

Threat Assessment

Severity Level

LOW

Attack Vector Rugpull
Root Cause Exchange (DEX)
Year 2021

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