Bart Stephens, the co-founder and managing partner of Blockchain Capital, a prominent crypto fund, has taken legal action against an anonymous hacker, known as Jane Doe, who stole $6.3 million worth of bitcoin, ether, and other cryptocurrencies from his digital wallets.
The hacker used personal information available online and on the dark web to perform a SIM-swap attack, changing account passwords and gaining control of Stephens’ cellular network account. This enabled them to port Stephens’ private cell number to a new device, allowing unauthorized access to his digital assets.
The lawsuit, filed in the United States District Court for the Northern District of California, alleges that the hacker exploited a well-known method called a SIM-swap attack. Such attacks, warned about by the Federal Bureau of Investigations (FBI), have become increasingly common and target individuals likely to own substantial amounts of cryptocurrency. The FBI estimated that $72 million was stolen through SIM-swap attacks in the previous year, indicating the growing threat.
Blockchain Capital, founded by Stephens in 2013 with his brother Brad Stephens, has backed several crypto startups, including Coinbase, Kraken, and Opensea. Stephens’ lawsuit claims that the hacker bypassed security measures and began systematically stealing his digital assets by resetting passwords and passing two-factor authentication checks at multiple unnamed digital wallets.
The hacker also attempted to steal around $14 million worth of bitcoin and ethereum from a custodial cold wallet owned by Stephens but was thwarted by a Blockchain Capital employee who had been alerted to the withdrawal attempt.
