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A Bitcoin holder has come forward, claiming to be the victim of a hack that resulted in a staggering $3 million transaction fee, setting a new record for Bitcoin transaction costs.

Last Thursday, the Bitcoin community witnessed an unusual transaction where a user seemingly paid a fee of 83.65 BTC, amounting to over $3.1 million. This transaction broke the previous U.S. dollar record for a single Bitcoin transaction fee, which was around $500,000 in September.

The day after this incident, an individual claiming to be the victim opened a new X account with the username “@83_5BTC,” mirroring the fee amount. This user shared their story: “I created a new cold wallet, transferred 139 BTC 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.”

In the transaction in question, an 83.65 BTC fee was used to transfer 55.77 BTC, valued at approximately $2.1 million, from a total pre-transaction balance of 139.42 BTC, or $5.2 million. “55 BTC gone forever. 83.5 BTC to be decided,” lamented 83_5BTC.

Verification of Ownership

To substantiate their claim, 83_5BTC signed a message from the Bitcoin address involved, affirming, “@83_5BTC is the owner of the funds that paid the high fee.” This signature was verified by Mononaut, the pseudonymous developer behind Bitcoin explorer Mempool. “The signature checks out, @83_5BTC apparently controls the key that paid that 83.7 BTC fee,” Mononaut confirmed. Jameson Lopp, co-founder and CTO of Casa, also verified the signature.

However, Mononaut cautioned that if the wallet had been compromised, it’s possible the message could have been signed by the hacker. The transaction was processed by AntPool in block 818,087, as per Blockchair, a blockchain explorer. The previous record fee of $500,000, identified as an error by crypto services provider Paxos, was refunded by F2Pool, the miner involved in that transaction. Whether AntPool will agree to a similar arrangement is uncertain, and should it choose to, they would require an alternative method to authenticate the victim’s identity.