Harmony weighs rollback after alleged minting of 4B ONE

Harmony is weighing a rollback after reports an attacker minted nearly 4 billion ONE tokens, about 26% of the token’s supply. The project posted that it is coordinating with exchanges to stop and freeze funds, preparing a software patch and assessing rollback options. The project did not confirm the cause of the incident, the exact number of tokens created or how many tokens may have been moved to trading platforms. Requests for comment were not answered by publication.

An account on X calling itself Juiceberg claimed the unauthorized tokens were minted through empty blocks and that about 2.8 billion ONE were quickly funneled to exchange deposit wallets as the token’s price dropped. Juiceberg estimated the attacker still held about 115 million ONE onchain, roughly 2.9% of the amount allegedly minted, with the remainder either sold or held at exchanges. Those figures have not been independently verified.

Market data showed ONE’s price fell about 33.9% over the preceding 24 hours.

If Harmony implements a rollback, it would revert the chain to a prior state to remove the unauthorized token creation. That action would alter transaction history and account balances on the network. The team said it was assessing options but gave no timeline or final decision.

The incident recalls Harmony’s June 2022 Horizon Bridge breach, which resulted in the loss of roughly $100 million in cryptocurrency and was later attributed by U.S. authorities to the Lazarus Group. Investigators and market participants are monitoring developments as Harmony and exchanges work to contain the fallout and confirm the scope of the suspected exploit.