AntPool Considers Refund After $3 Million Bitcoin Transaction Fee Blunder

A Bitcoin user who paid a whopping $3 million fee for a single transaction may get a refund from AntPool, the mining pool that processed it. AntPool announced that it has frozen the fee and is waiting for the owner to verify their identity before returning it.

Learn 2 Trade previously reported that the user sent 55.77 BTC ($2.1 million) and mistakenly paid 83.65 BTC ($3.1 million) as a gas fee, overshooting the mark by over 120,000 times. This unprecedented transaction, mined by AntPool in block 818,087 on November 23rd, set a new record for the highest fee in U.S. dollar terms.

Antpool Lays Out the Refund Process for the Bitcoin Transaction as a New Twist Emerges

According to The Block, AntPool has taken a proactive approach, urging the user to verify their identity before December 10th. The user is required to sign a message with the private key of the sending address, including the word “AntPool,” and forward it to the support email address.

However, doubts arise about the legitimacy of the user’s claim as another individual purports to be a victim of a hack on X, asserting that their wallet was compromised, resulting in the exorbitant fee payment. This user claims to have lost 55 BTC and is uncertain about the fate of the remaining 83.5 BTC.

It was my BTC that paid the high fee.

I created a new cold wallet, transferred 139BTC to it and it got transferred out to another wallet immediately. 😵

I can only imagine that someone was running a script on that wallet and that the script had a weird fee calculation. ☹️

— Hackers_paid_83.5BTC_fee_with_my_money (@83_5BTC) November 24, 2023

While the claimant signed a message with the same key, verified by Mononaut, the developer of Bitcoin explorer Mempool, Mononaut emphasizes the potential of the key being pilfered by an attacker. This adds a layer of complexity to AntPool’s verification process, raising questions about the actual owner of the funds.

Speculation surrounds the hack’s origin, with suggestions pointing towards a low-entropy wallet vulnerability, possibly a brainwallet, that facilitated the breach. The transaction’s fee was also manipulated using replace-by-fee (RBF), a feature allowing the increase of an unconfirmed transaction’s fee. Mononaut suggests that multiple attackers could have been competing for the funds, using the exorbitant fee as a deterrent.