How much was lost in the Cubic Finance hack?

The Cubic Finance hack resulted in $217K in losses on January 15, 2021.

What attack technique was used in the Cubic Finance exploit?

The Cubic 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.

Cubic Finance Hack

TOTAL LOST $217K

Low Jan 15, 2021 Rugpull ethereum

Affected Chain ethereum Incident surface

Recovered - No recovery reported

All-Time Rank #1264 By amount stolen

Auditors 1 Prior security audit

Incident Overview

The project was holding a presale event at:

https://app.bounce.finance/fixed-swap/5048

304 ETH were raised in total.

1. The contract deployer transferred tokens to the external wallet at:

https://etherscan.io/tx/0x08779ce4…a805ec

2. The token recipient added initial and further liquidity at:

https://etherscan.io/tx/0xcff977ee…816858

https://etherscan.io/tx/0xb97cfbb3…1074bf

3. Only 18.23 / 304 ETH was used to add liquidity. In addition, the token was listed on the Hotbit exchange:

https://hotbit.zendesk.com/hc/en-us/articles/360060184974-Hotbit-will-launch-CUBIC-Cubic-Finance-on-January-15th-2021

4. The token recipient from step 2 transferred part of tokens to the other external wallet at:

https://etherscan.io/tx/0x84c16aa1…4ac41c

5. This external wallet deposited received tokens directly to the Hotbit exchange so further actions can't be tracked. Stolen funds were calculated based on the raised funds from the presale event minus added liquidity amount.

Incident Report

Protocol / Project Cubic Finance

Date of Incident January 15, 2021

Affected Chain(s) ethereum

Attack Technique Rugpull

Classification Yield Aggregator

Primary Source View Post-Mortem

Protocol Information

Protocol Type Farm

Affected Token CUBIC

Official Website www.cubic.finance/

Protocol Twitter/X @cubicfinance

Market Context at Time of Hack

Token Categories

BNB Chain Ecosystem

Protocol Links

GitHub

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 Cubic 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

Audited by Audit Report 1 — still lost $217K. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to Cubic 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://twitter.com/DetectivesRug/status/1345749674356047875

Threat Assessment

Severity Level

LOW

Attack Vector Rugpull
Root Cause Yield Aggregator
Year 2021

Learn to Prevent the Next Cubic Finance

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