Intelligence agents have uncovered the largest-ever (or at least largest discovered) Bitcoin heist, amounting to 127,426 stolen Bitcoins. According to Arkham Intelligence on X , the heist was made against the Chinese mining pool LuBian in 2020, amounting to a value of $3.5 billion ($14.5 billion today).

LuBian was the 6th-largest mining pool on the Bitcoin network at its peak, before the pool disappeared in 2021. LuBian was so big that it controlled 6% of the Bitcoin network's total hash-rate capacity alone by May 2020. Ironically, LuBian was allegedly advertised as "the safest high-yielding mining pool in the world" before its disappearance.

Arkham believes the first hack occurred on December 28th, 2020, constituting over 90% of the mining pool's Bitcoin supply. A day later, another hack was executed, amounting to over $6 million of additional Bitcoin and USDT. On December 31st, LuBian moved what little coins it had left into recovery wallets.

The attack (Arkham believes) was conducted using brute-force attacks on LuBian's private key generation capabilities. LuBian's private key generation was allegedly using an extremely weak 32-bit entropy, allowing anyone with the processing power of a gaming computer and a few days to hack into LuBian's wallets.

LuBian is still holding onto its remaining 11,886 Bitcoins since the attack, and the hacker has done the same (and still holding onto all of the crypto it stole from LuBian). Arkham reports that the hacker's last known movement was a wallet consolidation in July 2024. LuBian's hacker got enough coin to make them the 13th-largest Bitcoin holder worldwide.

The LuBian hack is now considered the largest crypto hack in history, surpassing the Mt. Gox hacks in the early 2010s. Technically, the second Mt. Gox hack in 2014 consisted of significantly more stolen Bitcoins, amounting to 850,000 coins. But back then, the value of Bitcoin was far lower than it was in 2020, making LuBian's $3.5 billion hack (now worth $14.5 billion) far more profitable. (The second Mt. Gox Hack was valued at "just" $460 million worth of stolen Bitcoin by contrast.)