How much was lost in the Finiko hack?

The Finiko hack resulted in $1.5B in losses on July 05, 2021.

What attack technique was used in the Finiko exploit?

The Finiko 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.

Finiko Hack

TOTAL LOST $1.5B

Critical #10 All-Time Jul 05, 2021 Rugpull

Affected Chain 2021 Incident surface

Recovered - No recovery reported

All-Time Rank #10 By amount stolen

Protocol Type Exit Scam/Rugpull Target category

Incident Overview

Quick Summary

Finiko company which offers Bitcoin investment opportunities and huge return fees turns out to be a Ponzi scheme. The founders of the company were arrested. Finiko accumulated funds close to 1,500,000,000 $USD due to an investigation from Chainalysis.

Details of the Exploit

The company, named Finiko, offered lucrative investment options using a network of promoters who pulled in new users for referral fees. Investors were supposed to put in bitcoin and get the native token of Finiko in return.

About 100 people reported Finiko to the police, officials said, and the amount of claims totaled around 70 million Russian rubles, or slightly less than $1 million. The project accumulated 59,645 $BTC which is valued at more than 1,500,000,000 $USD due to an investigation from Chainalysis.

Block Data Reference

Scammer addresses:

https://www.blockchain.com/btc/address/328zFd28B4WpdGwuDSnYw7BAEtZQc41Lrk

https://www.blockchain.com/btc/address/1KDqdout1md6fJBDo3LqRdAuiqjw8Twxn5

Full list of the involved addresses:

https://archive.ph/8m2yG

Incident Report

Protocol / Project Finiko

Date of Incident July 05, 2021

Attack Technique Rugpull

Classification CeFi

Primary Source View Post-Mortem

Protocol Information

Protocol Type Exit Scam/Rugpull

Protocol Twitter/X @finiko_ru

Team Public / Doxxed

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 smart contracts and deploy a custom exploit contract

Protocol Analysis Identification of the exploitable vulnerability in Finiko's contract logic - root cause: cefi

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 Finiko, these are the critical security checks that could have prevented this incident (July 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://blog.chainalysis.com/reports/eastern-europe-cryptocurren…

Threat Assessment

Severity Level

CRITICAL

Attack Vector Rugpull
Root Cause CeFi
Year 2021

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