$3.5 Billion 2020 Bitcoin Heist Retroactively Exposed by Arkham Intelligence
In a shocking revelation, Arkham Intelligence has unveiled what is now confirmed as the largest cryptocurrency hack in history a 2020 breach that resulted in the theft of 127,426 Bitcoin (BTC), worth roughly $3.5 billion at the time and a staggering $14.5 billion at current market prices. The unprecedented digital heist targeted China-based mining pool LuBian, with both the exchange and hacker keeping the event concealed from the public for years.
Inside the Largest Bitcoin Hack Ever
According to Arkham, LuBian a mining operation that had quickly risen to become the sixth-largest BTC pool was compromised on December 28, 2020. During the attack, cybercriminals siphoned off about 90% of LuBian’s reserves before the platform managed to move the remaining 11,886 BTC to safe wallets. Arkham’s blockchain analysts discovered the magnitude of the incident years after the fact, noting that neither LuBian nor the hacker disclosed details at the time, effectively leaving one of the crypto sector’s most significant breaches unreported and undetected.
Technical Flaws Led to the Mega Heist
The investigation suggests that LuBian’s private key generation algorithm was flawed and vulnerable to brute-force attacks a critical weakness that the hacker exploited. In an attempt to warn or communicate with the attacker, LuBian embedded more than 1,500 OP_RETURN messages across the blockchain, a move that ultimately cost it 1.4 BTC in transaction fees.
Key Takeaways:
- Total BTC stolen: 127,426
- Current value: ~$14.5 billion
- Breach date: December 28, 2020
- Discovery: Uncovered by Arkham Intelligence in 2025
- Vulnerability: Weak private key generation exploited via brute force
Arkham emphasized that this breach underscores the importance of strong cryptographic standards, robust private key management, and using only secure, random number generators for wallet creation.
How the LuBian Hack Compares to Other Major Crypto Heists
Although the $1.5 billion ByBit exchange hack in February 2025 previously held the record for the largest single crypto theft, the LuBian incident eclipses it by more than double even at 2020 prices. The ByBit theft was traced to a compromised SafeWallet developer’s device, which allowed attackers to abuse cloud credentials and access company systems undetected.
Other recent high-profile crypto thefts include a $330 million loss by an elderly U.S. victim in a sophisticated social engineering scheme. In that case, the funds were laundered through hundreds of unique wallets, complicating recovery efforts. Only $7 million was frozen in connection to that heist, highlighting the challenges of tracking and retrieving stolen digital assets across the blockchain.
Lessons for the Crypto Community: Security Comes First
This record-breaking incident serves as a wake-up call for crypto holders, mining pools, and institutions worldwide. As the value of cryptocurrency surges, so does the incentive for cybercriminals. The LuBian breach was enabled by weak private key generation, reinforcing the critical need for industry best practices:
- Always use tested, entropy-rich algorithms for wallet key generation
- Employ advanced, continually updated cryptographic security standards
- Monitor, audit, and diversify holdings to mitigate the risk of concentrated losses
Looking Ahead: Strengthening Blockchain Security
As blockchain technology becomes more mainstream, the sector must prioritize security, transparency, and user education. The rise in sophisticated attack vectors, such as brute-force and targeted social engineering, means both individuals and platforms need to remain vigilant and proactive in their defense strategies.
The unmasking of the $3.5 billion LuBian hack is a stark reminder: in the world of crypto, robust security and proactive defense are non-negotiable for safeguarding digital fortunes.