Harmony's ONE Sinks 37% After Attacker Mints 4 Billion Tokens

In brief

• Harmony confirmed an exploit after an analyst reported that an attacker minted about 4 billion ONE, roughly 26% of the supply.
• Around 97% of those tokens have already reached exchanges, on-chain analyst Juiceberg said.
• ONE was trading at about $0.00077, down 37% on the day, after Harmony shipped a patch to stop further minting.

Layer-1 blockchain Harmony has confirmed it was exploited after an attacker minted roughly 4 billion ONE tokens without authorisation, sending the token down 37% to about $0.00077, per CoinGecko data.

On-chain analyst Juiceberg flagged the mint early Wednesday, putting it at close to 4 billion tokens, or about 26% of the supply, and saying the tokens had been created through empty blocks. Around 2.8 billion were funnelled onto exchanges as the price fell.

In a follow-up tweet, the analyst said the attacker had roughly 115 million ONE left to sell on-chain, about 2.9% of the total minted. "The overwhelming majority (~97%) is already on exchanges," Juiceberg wrote, and had either been sold or was sitting in deposit wallets.

Harmony responded in a tweet that it was "working with our team and appropriate exchanges to stop and freeze the funds," adding that it was preparing a patch and weighing rollback options. In a second post it named four wallets, each listed in both Harmony and hex formats, and asked exchanges to block anything traced to them.