Crypto Wallet SecondFi Hacked: $2.4M Stolen, Up to $20M at Risk

A flaw in SecondFi's Cardano wallet let hackers steal 16 million ADA across three attacks, with losses potentially topping $20 million.

A popular crypto wallet just got hacked, and users are losing real money. SecondFi, a digital wallet (a tool used to store cryptocurrency) for the Cardano network, was attacked three separate times — draining about $2.4 million from hundreds of users.

Here's what happened: SecondFi (formerly known as Yoroi) had a hidden flaw in its wallet generation software (the program that creates the digital storage accounts where users keep their coins). Hackers found this weakness and used it to steal funds.

The key facts so far:

16 million ADA stolen — worth around $2.4 million — taken from 374 user wallets.
The attacks happened in three separate waves.
The team rescued a further 129 million ADA by quickly moving it to a safe, independent holder before hackers could grab it.
Security firm SlowMist warns total losses could top $20 million once everything is checked — though this figure isn't confirmed yet.

Why this is scary: Normally, crypto users protect their coins with a "seed phrase" (a secret list of words that acts like a master password). But in this case, moving your seed phrase to a new wallet won't help. The flaw is built into the wallet's address itself, and the danger triggers the moment a user approves a transaction (signs off on sending money).

ADA, Cardano's cryptocurrency (a digital coin), is currently trading around $0.15 — its lowest price since 2020.

Cardano's founder, Charles Hoskinson, admitted the hack happened but pointed out the dollar amount is small compared to bigger crypto thefts. Still, he acknowledged it hurts the people affected. "This is the unfortunate reality of crypto," he said.

What should affected users do? They cannot simply protect themselves on their own — instead, they must submit a claim directly to SecondFi. An outside accounting firm has been hired to verify the rescued funds.

The takeaway: This is a reminder that crypto wallets, even popular ones, can have hidden weaknesses. When you store money in a digital wallet, you're trusting the software behind it to keep your funds safe.

This is an AI-generated summary. Read the original article at: https://www.coindesk.com/business/2026/06/24/secondfi-loses-usd2-4-million-in-cardano-wallet-exploit-with-up-to-usd20-million-at-risk