Upbit Hack

TOTAL LOST $51.2M
High #124 All-Time Access Control

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain 2019 Incident surface
Recovered - No recovery reported
All-Time Rank #124 By amount stolen
Auditors 1 Prior security audit

Incident Overview

Quick Summary

On November 27, 2019, 342,000 ETH was transferred from the Upbit Ethereum hot wallet to an unknown wallet.

Block Data

ReferenceThe address of the unknown wallet:

https://etherscan.io/address/0xa09871ae…43c029

This is classified as a Access Control Attacks . Compare similar hacks →

Incident Report

Protocol / Project Upbit
Date of Incident
Attack Technique Access Control
Classification CeFi
Primary Source View Post-Mortem

Protocol Information

Protocol Type Lending
Official Website sg.upbit.com/
Protocol Twitter/X @upbitglobal
Team Anonymous
Source Code Unverified

Market Context at Time of Hack

Protocol Links

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 Operational-security tradecraft (phishing, malware, leaked seed phrases, or insider access) to obtain treasury signing authority
Capital Required Minimal capital - only enough to cover gas while draining the compromised accounts
On-Chain Access Valid signing authority over the compromised wallets / multisig signers, allowing direct transfer of funds or stake authorization
Target Reconnaissance Identification of Upbit's high-value treasury accounts and the authority / multisig structure controlling them
Execution Speed Speed to drain the compromised accounts before the team detects the breach and revokes signing authority or freezes the assets
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 Access Control audit checklist and test coverage
Audited by Audit Report 1 — still lost $51.2M. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to Upbit, these are the critical security checks that could have prevented this incident (November 2019).

  • Verify all logic paths related to Access Control are guarded by proper access controls and input validation - see the Access Control Attacks attack class for patterns
  • 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

Related Attack Classes

The technique used in this hack maps to these vulnerability classes in our security curriculum:

See all Access Control Attacks examples →

Access Control Attacks

Sources & References

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