Incident Overview
South Korean crypto exchange GDAC was hacked for 14,324,040 $USD. The hacker transferred 23% of GDAC's total assets under custody.
GDAC is a Centralized Exchange based in South Korea. On April 9th, a hack occurred in the Gdac Hot Wallet and 14,324,040 $USD worth of cryptocurrency was transferred to an unidentified wallet. The stolen assets include 60.8 $BTC, 350.5 $ETH, 220,000 $USDT, and 10,000,000 $WEMIX. This is approximately 23% of GDAC's total assets currently under custody. As soon as this was confirmed through their monitoring system, the emergency response team convened and began responding immediately by suspending all deposit and withdrawal services along with related servers being blocked. They reported the fact to the police requesting a cyber investigation while notifying Korea Internet & Security Agency (KISA) for technical support. FIU has been notified about this incident too.
GDAC urged asset issuers (foundations), exchanges, and DeFi managers to freeze assets further adding that they are doing their best by collaborating with various organizations.
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 GDAC, these are the critical security checks that could have prevented this incident (April 2023).
- Verify all logic paths related to Hot wallet hack / 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 GDAC
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