A Bitcoin user has recently come forward to report being the victim of a hack that resulted in a record-breaking $3 million Bitcoin transaction fee. This news has shocked the cryptocurrency community, raising concerns about the security of digital assets and the vulnerabilities in the blockchain system.
Unveiling the Hack
The anonymous user, known as @83_5BTC on X, explained that they had created a new cold wallet and transferred 139 BTC, equivalent to over $5 million, to it. Almost immediately after the transfer, the funds were siphoned off to another wallet. The user suspected foul play, suggesting that a script running on the wallet had an anomalous fee calculation. In a tweet on Friday, @83_5BTC expressed their frustration, stating, “I can only imagine that someone was running a script on that wallet and that the script had a weird fee calculation.”
Understanding the Record Fee
The incident occurred when a Bitcoin transaction on the blockchain incurred a fee of 83.65 BTC, amounting to $3.1 million. This fee broke previous records in terms of US dollar value for a single transaction on the network. The transaction was first noticed by prominent Bitcoin developer @Mononautical, who observed that it involved sending 55.77 BTC along with the unusually high mining fee.
@83_5BTC took to X and shared the address used for the transaction, receiving support from cryptography expert Jameson Lopp, who verified the signature checks.
“The most likely cause of this monumental fee was a low-entropy wallet vulnerable to hacking,” explained @Mononaut. He further added, “The transaction was expedited using replace-by-fee, where the sender can increase the fee on pending transactions to speed up confirmation. Multiple hackers may have targeted the vulnerable wallet, competing to swiftly extract the funds.”
This revelation sheds light on the abnormal fee, as the attackers may have implemented scripts designed to hinder other hackers by spending a significant portion of the transaction. Coincidentally, the transaction fee accounted for precisely 60% of the total 139.42 BTC balance taken from the compromised wallet, indicating that an automated script had been preset to allocate 60% of the funds as a fee.
Implications and Possible Reimbursement
The record fee transaction was mined by AntPool in block 818,087, surpassing the previous high set in September, when Paxos mistakenly overpaid F2Pool by $500,000. In that instance, F2Pool returned the fee to Paxos following the transaction. It remains uncertain whether AntPool would consider a similar reimbursement agreement for the recent record fee incident.
While the user behind @83_5BTC claims ownership of the funds, the exact details of the hack are still unknown. The Bitcoin community is actively investigating the addresses and transactions involved in hopes of uncovering more information. Blockchain analysis could potentially be utilized to trace the destination of the stolen funds and identify patterns that may lead to the hackers. However, exchanging or mixing the Bitcoin through tumblers could make it harder to follow the money trail.