ONE Token Plummets 37% After Harmony Exploit

Harmony's native token ONE plummeted by 37% after an attacker exploited a vulnerability to mint approximately 4 billion tokens, roughly 26% of its supply. The attack occurred on August 12, with around 97% of the newly minted tokens already reaching exchanges. On-chain analyst Juiceberg initially reported the exploit, noting that the tokens were created through empty blocks.

The attacker had funnelled approximately 2.8 billion ONE onto exchanges as the price fell. In a follow-up tweet, Juiceberg stated that the overwhelming majority (around 97%) of the minted tokens was already on exchanges and had either been sold or was sitting in deposit wallets. The attacker retained roughly 115 million ONE to sell on-chain, approximately 2.9% of the total minted.

Harmony responded quickly, releasing a patch to prevent further minting and advising validators to upgrade to the latest build. However, dealing with the already created tokens would require another update. The project has not disclosed the vulnerability or confirmed how many tokens were created, nor have they stated how much reached exchanges.