Incident Overview
Bithumb suffered an insider attack leading to abnormal withdrawals but managed to recover approximately $14m.
Bithumb detected unusual withdrawals through their monitoring system. The incident was an "accident involving insiders." The exchange's EOS hot wallet began sending EOS to the attacker's address. The company realized the attack was ongoing and started to move the funds to the cold storage wallet, which was not compromised.
Bithumb admitted that it had only focused on protection from outside attacks and did not verify its staff.
The attacker's address:
https://bloks.io/account/ifguz3chmamg
The exchange hot wallet:
https://bloks.io/account/g4ydomrxhege
Bithumb's claim about $14m recovery:
https://www.econotimes.com/Bithumb-claims-recovery-of-14M-in-hacked-cryptocurrencies-1396613
Incident Report
Protocol Information
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.
What Auditors Should Check
If you're auditing a protocol with similar architecture to Bithumb, these are the critical security checks that could have prevented this incident (March 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.
Free TrialFunds Recovery
Recovered
$14.0M
Net Loss
5203199
Related Attack Classes
The technique used in this hack maps to these vulnerability classes in our security curriculum:
Sources & References
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