Harmony ONE Plunges 40% After $20B Token Mint Exploit

Harmony's ONE token has plummeted nearly 40% in value after an attacker reportedly created approximately 4 billion tokens without authorization and transferred billions towards centralized exchanges.

The attack, which occurred on August 12, exposed a supply-accounting problem that allowed the newly created tokens to remain hidden from conventional checks while the transactions were occurring. Onchain researcher Juiceberg estimated that around 2.8 billion ONE were routed towards exchanges, increasing the amount available for liquidation.

Harmony is working with exchanges to freeze the affected funds and developers are preparing a patch and evaluating possible rollback options. The project has not yet confirmed the exact mechanism behind the attack or provided a final loss estimate.

This incident marks another major security crisis for Harmony, following the $100 million Horizon Bridge theft in June 2022 attributed to North Korea's Lazarus Group.