How much was lost in the AFKSystems Finance hack?

The AFKSystems Finance hack resulted in $2.0M in losses on September 10, 2021.

What attack technique was used in the AFKSystems Finance exploit?

The AFKSystems 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.

AFKSystems Finance Hack

TOTAL LOST $2.0M

Medium Sep 10, 2021 Rugpull

Affected Chain 2021 Incident surface

Recovered - No recovery reported

All-Time Rank #645 By amount stolen

Protocol Type Exit Scam/Rugpull Target category

Incident Overview

The EOA address deployed unverified smart contract at:

https://polygonscan.com/tx/0x371b8da1…341eb5

This smart contract interacted with different MasterChef contracts:

https://polygonscan.com/tx/0xa4dafd21…3fe470

https://polygonscan.com/tx/0x5a27947b…028de9

https://polygonscan.com/tx/0x758ca246…541e8b

https://polygonscan.com/tx/0xcb729d6c…d5038f

https://polygonscan.com/tx/0x80fc64a2…47860f

The bytecoded contract had approval for spending LP tokens, as a result, funds were transferred to the external address:

https://polygonscan.com/address/0x0a301bdf…6109e7

Withdrawn LP tokens were used to remove liquidity at:

https://polygonscan.com/tx/0xf68759da…099dc8

https://polygonscan.com/tx/0x9f4d43f1…91a155

Incident Report

Protocol / Project AFKSystems Finance

Date of Incident September 10, 2021

Attack Technique Rugpull

Classification Yield Aggregator

Primary Source View Post-Mortem

Protocol Information

Protocol Type Exit Scam/Rugpull

Affected Token SILVER

Official Website afksystem.finance/

Protocol Twitter/X @AFKSystemFi

Market Context at Time of Hack

Token Categories

Solana Ecosystem PetRock Capital Portfolio

Protocol Links

GitHub Discord

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 AFKSystems Finance'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

If you're auditing a protocol with similar architecture to AFKSystems 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://afksystem.finance/
02
Web Archive https://web.archive.org/web/20210817074609/https://afksystem.finance/

Threat Assessment

Severity Level

MEDIUM

Attack Vector Rugpull
Root Cause Yield Aggregator
Year 2021

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