Incident Overview
Licensed Japanese crypto exchange Zaif was hacked, and 59,000,000 $USD worth of assets was stolen in $BTC, $BCH and MonaCoin
The licensed exchange, called Zaif, is operated by the Tech Bureau. It said on Thursday that the exchange first noticed an unusual outflow of funds on the platform around 17:00 Japan time on September 14, after which the company suspended asset deposit and withdrawal services.
Tech Bureau explained that after further investigation, it discovered that hackers with unauthorized access to the exchange's hot wallets had stolen roughly $60 million in Bitcoin, Bitcoin Cash, and MonaCoin. That being said, the exact amount of bitcoin cash stolen remains unknown.
Tech Bureau said given the nature of the unauthorized fund access, it has filed the incident as a criminal case to local authorities for further investigation.
Incident Report
Protocol Information
Market Context at Time of Hack
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 Zaif, these are the critical security checks that could have prevented this incident (September 2018).
- 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 TrialRelated Attack Classes
The technique used in this hack maps to these vulnerability classes in our security curriculum:
Sources & References
Learn to Prevent the Next Zaif
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