Currently recognised as the largest crypto theft in history, Chinese Bitcoin mining pool LuBian was the victim of a staggering 127,426 BTC heist in December 2020.
At the time, the stolen Bitcoin was worth approximately $3.5 billion, but with BTC’s current price surge, the haul is now valued at $14.5 billion, according to blockchain analytics firm Arkham Intelligence.
LuBian, once a dominant player controlling 6% of the Bitcoin network’s hash rate, mysteriously vanished in early 2021. The shutdown was long attributed to regulatory pressures, but Arkham’s findings now point to a massive, undisclosed cyber breach as the real reason.
BTC's price trends to the upside on the daily chart. Source: BTCUSD on Tradingview
A Flawed Private Key and a Silent Giant
The hackers reportedly exploited weak private key generation, a fundamental security flaw that allowed them to drain over 90% of LuBian’s BTC in a single attack on December 28, 2020. Two days later, an additional $6 million in BTC and USDT was siphoned from another LuBian-linked wallet operating on the Bitcoin Omni layer.
In a desperate attempt to recover the funds, LuBian issued over 1,500 Bitcoin transactions embedded with OP_RETURN messages, directly pleading with the attacker to return the stolen BTC. Despite these efforts, no response was ever received.
Today, that hacker’s wallet has gone largely untouched, with its last significant movement being a wallet consolidation in July 2024. According to Arkham, this dormant address is now the 13th largest Bitcoin wallet in existence, ahead of the infamous Mt. Gox hacker.
How the Bitcoin Heist Implicates Crypto Security
This massive breach not only surpasses all previous crypto hacks, including the $1.5 billion Bybit exploit of 2025, but also exposes deep vulnerabilities in older blockchain infrastructure and private key protocols.
With $3.1 billion already lost to crypto hacks in the first half of 2025, experts are urging mining pools and exchanges to strengthen security practices.
As the LuBian case resurfaces, it serves as a stark reminder: in crypto, weak security can cost billions, and stay hidden for years.
Cover image from ChatGPT, BTCUSD chart from Tradingview
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