Harmony has moved from considering a rollback to publishing the exact checkpoints it plans to use after an attacker forged trillions of ONE tokens. The recovery decision will discard legitima
Harmony has moved from considering a rollback to publishing the exact checkpoints it plans to use after an attacker forged trillions of ONE tokens. The recovery decision will discard legitimate post-checkpoint activity as well as the malicious state, making it one of the most disruptive options available to a live blockchain.
In an August 17 incident update, Harmony said validators will use replacement databases at shard 0 block 92,730,034 and shard 1 block 94,978,278. Both correspond to August 11 at 23:25:37 UTC.
The first confirmed forged mint entered shard 0 at block 92,730,036. Harmony selected block 92,730,034 as a one-block safety buffer because the intervening block contained no regular or staking transactions, incoming receipts, or gas use and had the same state.
Shard 1 was not where the forged mint occurred, but the team included it as a precaution at the same timestamp. New blocks will begin at heights 92,730,035 and 94,978,279 after validators switch to the replacement databases.
Harmony said it considered targeted burns, wallet blacklists, token migration, selective transaction replay, and a simpler database rewind. It rejected those approaches because the forged ONE had moved through exchanges, decentralized exchange pools, contracts, bridges, staking positions, and shared wallets. Removing balances selectively could therefore damage unrelated users or leave inconsistent state behind.
One forged-mint wallet attempted 534 transfers of 5 billion ONE in 106 seconds. Harmony said 477 transfers succeeded and moved 2.385 trillion ONE. Its later flow model reconciled almost all of the forged amount across service boundaries and transaction fees.
The team emphasized that tracing tokens to a wallet, pool, exchange, or service does not identify an individual and does not make the funds safely burnable. Shared balances can contain assets belonging to many unrelated users. Harmony said it is working with exchanges, bridges, law enforcement, and an independent security firm as the investigation continues.
The affected shard-0 archive contains 141,628 consecutive blocks and 109,126 regular transactions, plus 315 staking transactions. Harmony classified 95.8% of regular transactions as automated, but that still leaves real activity that cannot be restored safely.
Balances, nonces, pool reserves, approvals, swap deadlines, and staking state will change on the replacement chain. Replaying an old transaction could therefore produce a different result or cause a previously failed transaction to succeed.
The incident reinforces the operational risks behind cross-chain and decentralized-market infrastructure, already visible in the rapid growth of perpetual DEX activity. Harmony’s plan may remove the forged state, but execution now depends on validator coordination and on exchanges and bridges handling the discontinuity without crediting transactions from the discarded chain.
