A large Bitcoin theft from December 2020 has been exposed, becoming the largest cryptocurrency hack in history.
According to Arkham Intelligence, hackers stole 127,426 BTC from LuBian, a mining operation in China. The stolen Bitcoin was worth $3.5 billion at the time. Due to the increase in Bitcoin price, these assets are now worth $14.5 billion.
LuBian exploit is the largest cryptocurrency hack in history
LuBian operated mining facilities in China and Iran. In 2020, they controlled nearly 6% of Bitcoin's total hash rate.
Arkham's on-chain analysis shows that over 90% of LuBian's BTC was withdrawn on December 28, 2020. Additional funds were stolen two days later from a Bitcoin Omni Layer address.
Neither LuBian nor the hackers have publicly acknowledged the breach. The funds remained inactive until a consolidation event in July 2024.
Arkham researchers linked multiple addresses used in the theft and observed each address receiving OP_RETURN messages from LuBian. The mine spent 1.4 BTC across 1,516 transactions to call for the return of stolen funds.
This pattern strongly indicates that the hack was real and not fabricated. The hackers have not moved the stolen BTC again.
Arkham suspects LuBian used a faulty key generation algorithm that may have exposed their private keys to brute-force attacks. LuBian still holds approximately 11,886 BTC worth $1.35 billion.
Meanwhile, the hackers' treasury remains untouched, making them the 13th largest BTC holder globally.
This revelation surpasses the previous record—the Bybit hack worth $1.5 billion in February 2025.
Arkham's disclosure adds new urgency to reviewing key security and cryptocurrency infrastructure, especially in older mining operations.
