AntPool to Return $3 Million Bitcoin Transaction Fee

Bitcoin mining cooperative AntPool has decided to refund last week’s record-breaking $3 million transaction fee, subject to user verification. A user unintentionally paid an exorbitant fee, setting a new USD record for a single Bitcoin transaction.

On November 23rd, a user submitted 83 BTC as a gas fee, prompting AntPool’s risk control system to freeze the fee during transaction packaging temporarily.

To receive the refund, the original owner of the funds must use a signing tool such as Electrum or Bitcoin Core to verify their identity and send the signed text to AntPool’s support email address before December 10, 2023.

The user’s erroneous transaction involved paying a $3.1 million fee to transfer $2.1 million, resulting in a 120,528-fold overpayment. AntPool mined the transaction in block 818,087 but had not addressed the issue publicly until now.

The incident comes after the miner F2Pool reimbursed a previous record $500,000 fee paid in September, dubbed a “fat finger” overpayment.

In this recent case, a user claiming to be the victim claimed that their wallet had been hacked, resulting in a large fee payment.

The user stated that he created a new cold wallet, transferred 139 BTC to it, and then witnessed an instant transfer to another wallet.

According to Mononaut, the pseudonymous developer behind Bitcoin explorer Mempool, the use of a low-entropy wallet, possibly a brainwallet, was the likely cause of the hack.

The compromised wallet was quickly fee-bumped using the replace-by-fee (RBF) protocol feature, indicating potential competition for the funds among attackers.

While AntPool works to refund the unusual fee, concerns remain about the user’s identity verification, given the possibility of a compromised wallet.

The incident emphasizes the importance of secure wallet practices as well as the ongoing challenges associated with accidental and high-value crypto transactions.