How much was lost in the x20 finance hack?

The x20 finance hack resulted in $3K in losses on November 17, 2020.

What attack technique was used in the x20 finance exploit?

The x20 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.

x20 finance Hack

TOTAL LOST $3K

Low Nov 17, 2020 Rugpull ethereum

Affected Chain ethereum Incident surface

Recovered - No recovery reported

All-Time Rank #2004 By amount stolen

Auditors 1 Prior security audit

Incident Overview

The contract deployer invoked mint transaction and generated 50 thousand X20 tokens onto his wallet:

https://etherscan.io/tx/0xe6222931…d1d855

Most of them were added into liquidity at:

https://etherscan.io/tx/0xff2d791a…93a0a6

Part of them was sold in the following transactions:

https://etherscan.io/tx/0x7917b57c…0a6682

https://etherscan.io/tx/0x91ea88c9…f02075

https://etherscan.io/tx/0xae127f55…19984a

https://etherscan.io/tx/0xc260eb01…63a18a

1 day after, the liquidity was deleted:

https://etherscan.io/tx/0xe558685b…4c92b6

Incident Report

Protocol / Project x20 finance

Date of Incident November 17, 2020

Affected Chain(s) ethereum

Attack Technique Rugpull

Classification Token

Primary Source View Post-Mortem

Protocol Information

Protocol Type Onchain Capital Allocator

Affected Token X20

Official Website d2.finance/strategies

Protocol Twitter/X @D2_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 x20 finance's contract logic - root cause: token

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 $3K. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to x20 finance, 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.

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Security Audit History

Audit Report 1 Report

Sources & References

01
Source 1 https://twitter.com/CaptainJackAPE/status/1328302322011652098

Threat Assessment

Severity Level

LOW

Attack Vector Rugpull
Root Cause Token
Year 2020

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