Incident Overview
On June 21, 2025, the Hacken bridge was exploited due to a leaked private key associated with a minting role, leading to the unauthorized minting of 900 million HAI tokens and causing approximately $250,000 in losses. The HAI token price collapsed by around 99%, and the team responded by revoking access, pausing the bridge, and committing to a token migration that excludes the attacker’s funds.
The exploit occurred after a human error during a bridge architecture update exposed a private key with minting permissions; the attacker used this to mint 900 million HAI tokens on both Ethereum and BNB Chain. They sold the tokens primarily on BNB Chain, causing a rapid price collapse due to limited liquidity. The core deployer wallet was not compromised, allowing the team to quickly halt operations, but the absence of a multisig setup left the system vulnerable to this single point of failure.
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 Hacken Token, these are the critical security checks that could have prevented this incident (June 2025).
- Verify all logic paths related to Private Key Compromised / 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 Hacken Token
The Hacken Token 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.