SecondFi shuts down after $2.6 million ADA theft

The Cardano-focused wallet provider SecondFi announced on Wednesday, July 22, 2026, that it will permanently shut down its services following a major security breach that resulted in the theft of approximately 16.1 million ADA, valued at roughly $2.6 million. The incident, which affected 374 user wallets, was caused by a cryptographic flaw in the company's own wallet software that allowed attackers to derive private keys from transaction data visible on the Cardano blockchain.

According to an official statement from the company, an independent investigation conducted by blockchain intelligence firm Groom Lake identified a sophisticated external actor behind the attack. The investigation found indicators potentially linked to North Korea's Lazarus Group, though the company clarified that no formal attribution has been confirmed. The Cardano network itself was not compromised, and users of hardware wallets were not affected.

The breach occurred between June 21 and June 23. Nearly a month after initially disclosing the exploit in late June, SecondFi confirmed it would wind down both its SecondFi wallet and the Yoroi wallet service it replaced, which was originally developed by...