EXMO Hack

TOTAL LOST $11.7M
High Access Control

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain 2020 Incident surface
Recovered - No recovery reported
All-Time Rank #287 By amount stolen
Protocol Type CEX Target category

Incident Overview

Quick Summary

EXMO exchange suffered a security breach with large withdrawals from its hot wallets on December 21st.

Details of the Exploit

EXMO, a cryptocurrency exchange, reported large withdrawals from its hot wallets on December 21st starting at 2:27:02 UTC. The security audit revealed that various cryptocurrencies including BTC, XRP, ZEC, USDT, ETC, and ETH were moved out of the exchange. The impacted hot wallets accounted for approximately 5% of the total assets held by EXMO.

The exchange has since re-deployed its hot wallets. The hackers were able to withdraw the stolen funds to multiple addresses.

Block Data Reference

BTC Attacker Address:

https://www.blockchain.com/btc/address/1A4PXZE5j8v7UuapYckq6fSegmY5i8uUyq

USDT (ERC20) Attacker Address:

https://etherscan.io/address/0x4BA6B2fF…9F50Ce

ETH Attacker Address:

https://etherscan.io/address/0x4BA6B2fF…9F50Ce

BCH Attacker Address:

https://explorer.bitcoin.com/bch/address/qrfrw5q9gag2vp6jc5nlx0haplm2jlhx9vsvxd9u3e

ZEC Attacker Address:

https://explorer.zcha.in/accounts/t1StUQiw1YyHT515xDxwxjfhEcw2iGSq2yL

XRP Attacker Address:

https://xrpscan.com/account/rwU8rAiE2eyEPz3sikfbHuqCuiAtdXqa2v

ETC Attacker Address:

https://blockscout.com/etc/mainnet/address/0x4d9EF684…2C971e/transactions

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

Incident Report

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

Protocol Information

Protocol Type CEX
Official Website exmo.com/
Protocol Twitter/X @Exmo_Com
Team Anonymous
Source Code Unverified

Market Context at Time of Hack

Token Categories
Services Payments Ethereum Ecosystem Polygon Ecosystem Cardano Ecosystem Alleged SEC Securities Binance Ecosystem Binance Listing
Protocol Links
GitHub Reddit

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 EXMO'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

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

  • 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.

Free Trial

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

Browse all hacks

These hacks used the same attack technique. Understanding the pattern helps prevent future exploits.

BonkDAO $21.0M
Access Control
Token of Power $472K
Access Control
Humanity Protocol $31.0M
Access Control
Tessera DAO $2.4M
Access Control
Gravity Bridge $5.4M
Access Control
Stake DAO $91K
Access Control

Learn to Prevent the Next EXMO

The EXMO hack is one of many attacks that skilled auditors are trained to detect before deployment. Master real exploit patterns and defense techniques with hands-on Web3 security training.

Start Free Trial Browse Attack Library
Recreate exploit patterns safely Free Trial