Chainflip to reset TRON USDT provider balances to zero following $736,000 exploit

Chainflip will set affected liquidity providers’ active TRON USDT balances to zero under a restart plan responding to the 736,442.17 USDT exploit it disclosed on Sept. 12.

The cross-chain swap protocol will first record each provider’s pre-migration balance separately on-chain, preserving the amount Chainflip says it owes even though the active account will read zero. Repayment remains pending.

By Sept. 16, Chainflip said swaps and quoting had resumed across the rest of the network while TRON remained excluded. The service restart leaves providers on the affected route waiting for both the accounting migration and a recovery process.

Chainflip said the attacker removed the USDT from its TRON vault between 01:44 and 03:10 UTC on Sept. 12 by causing six liquidity-provider withdrawals to be paid twice.

The attack exploited how the protocol read instructions attached to TRON transfers. Chainflip said the attacker submitted a transaction its validators had already signed and added a malformed memo. Software monitoring the transfer interpreted the memo as a failed swap and issued a refund on top of the ordinary withdrawal.

The protocol said the TRON vault now holds far less USDT than providers are owed. The restart plan therefore separates the live account balance from the amount tracked for recovery.

How Chainflip will account for the shortfall

Chainflip’s migration plan calls for closing its open TRON/USDT orders and strategies and unwinding related loans and lending positions. The protocol and its software release use the label “trxUSDT” for USDT on TRON.

Each provider’s pre-migration trxUSDT amount will then be written to a separate on-chain balance before the active account balance is reset. Chainflip said this separate record keeps the amount owed available for future payouts.

The recorded amount is distinct from a completed reimbursement, and the provider’s live trxUSDT account will display zero after the migration.

Chainflip has pledged to make affected providers whole. Its public updates do not identify a funding source or payout schedule, document completed payments, or state a definitively recovered amount.

The protocol said it patched the vulnerability by limiting which TRON transfers can carry swap instructions in a memo. The new logic accepts memos attached to a plain TRX transfer or a direct TRC-20 token transfer. It excludes transfers wrapped inside another contract call, blocking the route used to trigger the extra refund.

Chainflip said all other funds were unaffected. The disclosed shortfall, position unwind, and balance reset apply specifically to trxUSDT liquidity providers.