How much was lost in the YFFC hack?

The YFFC hack resulted in $72K in losses on November 06, 2020.

What attack technique was used in the YFFC exploit?

The YFFC 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.

YFFC Hack

TOTAL LOST $72K

Low Nov 06, 2020 Rugpull ethereum

Affected Chain ethereum Incident surface

Recovered - No recovery reported

All-Time Rank #1625 By amount stolen

Protocol Type Exit Scam/Rugpull Target category

Incident Overview

Quick Summary

Investors of the YFFC project lost approx. $72k collectively due to the project deployers right

Details of the Exploit

YFFC was supposed to be a platform that unites a variety of DeFi platforms, ensuring an easier navigation through the crypto space for users. However, the smart contract contained a function that allowed contract deployer to mint as many $YFFC token as desired.

The contract deployer added initial liquidity at:

https://etherscan.io/tx/0x02cf382c…355d94

Almost 2 months after adding liquidity and once the $YFFC token was trading at an acceptable price for the contract deployer, the exploit started.

The contract deployer invoked the mint() function to generate new tokens onto the external wallet at:

https://etherscan.io/tx/0x39cecb2f…d99064

The external wallet sold newly minted tokens almost immediately at:

https://etherscan.io/tx/0xc3d42e64…c88c5f

Block Data Reference

Contract Deployer:

https://etherscan.io/address/0xe28db60e…c99ec4

Scammer Address B:

https://etherscan.io/address/0xa360d8e3…330a9a

Incident Report

Protocol / Project YFFC

Date of Incident November 06, 2020

Affected Chain(s) ethereum

Attack Technique Rugpull

Classification Yield Aggregator

Primary Source View Post-Mortem

Protocol Information

Protocol Type Exit Scam/Rugpull

Affected Token YFFC

Official Website yffc.finance/

Team Anonymous

Source Code Unverified

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 YFFC'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 YFFC, these are the critical security checks that could have prevented this incident (November 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.

Free Trial

Sources & References

01
Source 1 https://web.archive.org/web/20201108000455/https://twitter.com/F…
02
de.fi Analysis https://t.me/defiyield_ann/189
03
Web Archive https://web.archive.org/web/20200910031133/https://yffc.finance/

Threat Assessment

Severity Level

LOW

Attack Vector Rugpull
Root Cause Yield Aggregator
Year 2020

Learn to Prevent the Next YFFC

The YFFC hack is one of many attacks that skilled auditors are trained to detect before deployment. Master real exploit patterns and defense techniques with hands-on Web3 security training.

Start Free Trial Browse Attack Library