How much was lost in the SYFI hack?

The SYFI hack resulted in $250K in losses on September 10, 2020.

What attack technique was used in the SYFI exploit?

The SYFI exploit utilized Arithmetic Error. 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.

SYFI Hack

TOTAL LOST $250K

Low Sep 10, 2020 Arithmetic Error ethereum

Affected Chain ethereum Incident surface

Recovered - No recovery reported

All-Time Rank #1474 By amount stolen

Year 2020 Incident year

Incident Report

Protocol / Project SYFI

Date of Incident September 10, 2020

Affected Chain(s) ethereum

Attack Technique Arithmetic Error

Classification Token & Share Accounting

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 arithmetic error 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 SYFI's contract logic - root cause: token & share accounting

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? Likely, with a thorough Arithmetic Error audit checklist and test coverage

If you're auditing a protocol with similar architecture to SYFI, these are the critical security checks that could have prevented this incident (September 2020).

Verify all logic paths related to Arithmetic Error 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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Threat Assessment

Severity Level

LOW

Attack Vector Arithmetic Error
Root Cause Token & Share Accounting
Year 2020

Learn to Prevent the Next SYFI

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Incident Report

What the Attacker Needed to Succeed

What Auditors Should Check

Related Hacks - Arithmetic Error

Learn to Prevent the Next SYFI