tl;dr
Blockchain analytics firm Arkham revealed a previously unknown December 2020 hack of Chinese mining pool LuBian, resulting in the theft of 127,426 BTC, worth about $3.5 billion then and approximately $14.5 billion today. This is the largest crypto theft in history. The hack went unreported for over ...
Blockchain analytics firm Arkham has uncovered a previously unknown hack of Chinese mining pool LuBian in December 2020, leading to the theft of 127,426 BTC, valued at around $3.5 billion at the time. This hack ranks as the largest crypto theft in history, with the stolen Bitcoins now worth approximately $14.5 billion. Notably, neither LuBian nor the hacker publicly acknowledged the breach.
The hack went unreported for over four years and effectively drained nearly all of LuBian’s holdings. Once a top-ten global mining pool with 6% of Bitcoin’s hash rate, LuBian abruptly shut down in early 2021. While regulatory pressure was initially blamed for its closure, it is now attributed to this catastrophic security breach. Arkham's analysis indicates that over 90% of LuBian’s BTC was stolen in the initial December 2020 hack, followed by an additional theft of around $6 million in BTC and USDT from a Bitcoin Omni layer address later that same month.
Arkham suggests the theft resulted from weak private key generation vulnerable to brute-force attacks. Following the hack, LuBian attempted to recover the funds by sending over 1,500 small transactions totaling 1.4 BTC, including messages pleading for the return of the stolen assets, but to no avail. LuBian managed to preserve 11,886 BTC, worth about $1.35 billion today, which it still holds. Meanwhile, the hacker retains the stolen BTC, with their most recent wallet activity recorded in a consolidation transaction in July 2024. This makes the LuBian hacker the 13th largest Bitcoin holder on Arkham, surpassing the infamous Mt. Gox hacker.
The incident comes amid a turbulent period for the crypto industry. Cybersecurity firm Certik reported approximately $153 million lost to hacks and scams in July alone, with $86.6 million involving exchange breaches and $55.4 million due to code vulnerabilities. Hacken noted losses reaching $3.1 billion in the first half of 2025, marking DeFi’s worst quarter since early 2023. A surge in social engineering and AI-driven attacks largely fueled these staggering losses, which have already surpassed the total for 2024.