The Biggest Bitcoin Hack in History Revealed After 5 Years – Silent Thief Steals $14.5 Billion in BTC

Blockchain analytics platform Arkham has unveiled details of what is now considered the largest Bitcoin hack in history—a cyberattack that all parties involved tried to keep hidden for over five years.
According to CryptoRank, the incident targeted the LuBian protocol itself. At the peak of its operations, LuBian controlled roughly 6% of Bitcoin’s total network hash rate.

Investigations suggest the first breach occurred on December 28, 2020, when LuBian lost the majority of its holdings, followed by an additional $6 million in BTC stolen the next day. Neither LuBian nor the hacker has ever publicly acknowledged the incident—until Arkham brought it to light.

Following the breach, each wallet linked to the hacker received an OP_RETURN message on the Bitcoin blockchain. OP_RETURN is a Bitcoin script opcode that allows permanent, unspendable data to be stored on-chain. In these messages, LuBian pleaded with the attacker to return the stolen funds.

Sending these blockchain-embedded messages cost LuBian 1.4 BTC across 1,516 separate transactions, indicating they were authentic communications rather than fabricated warnings from third parties.

Security analysis points to a possible flaw in LuBian’s private key generation method, which may have been vulnerable to brute-force attacks—a hacking technique where all possible combinations are tested to guess a password or private key.

Although LuBian managed to safeguard 11,886 BTC (currently worth around $1.35 billion), the hacker still controls the stolen coins. In fact, the attacker is now ranked as the 13th largest Bitcoin holder on Arkham’s leaderboard, surpassing even the infamous Mt. Gox exchange hacker.