
$100M DRAINED From Crypto's Safest Wallet!
On July 30, 2026, over $100 million in Bitcoin was stolen from ColdCard hardware wallets in minutes. Thousands of users who did everything right were affected â their devices sat untouched in safes. The attack targeted not the hardware, but a 5-year-old firmware bug in the random number generator.
đ Technical Root Cause
- A flaw in the Libangu cryptography library caused the true hardware random number generator to be bypassed.
- Instead of 128 bits of entropy, the software fallback (Yasmarang) provided only 40 bits effective security (MK2/MK3) â MK4/MK5 had about 72 bits.
- 40 bits is so weak that a normal laptop can brute-force all possible seed phrases in hours offline.
đĄïž Who Was Safe?
Three groups remained untouched:
- Users who used at least 50 dice rolls during setup (true randomness).
- Users with a strong BIP39 passphrase (additional secret word).
- Users with genuine multisig (multiple keys from different devices).
â ïž Emergency Protocol for Affected ColdCard Owners
- Check if your seed was created between firmware 4.0.0 and 5.0.3.
- Assume the seed is compromised (unless you used dice, a strong passphrase, or multisig).
- Update firmware â this only protects new seeds, not old ones!
- Generate a new seed on patched firmware.
- Move funds now to the new wallet.
- Never reuse the old seed â treat it as public.
- Verify the receiving address on the device screen before sending.
Beware of phishing: Never enter your recovery phrase into a website, even one claiming to be a âvulnerability checker.â
đ CoinKiteâs Response & Lessons
- CEO NVK apologized publicly, halted shipments, and destroyed warehouse inventory with vulnerable firmware.
- The bug went undetected for 5 years because bad randomness shows no visible symptoms.
- Similar bugs existed in other projects (Libbitcoin, Profanity, Trust Wallet) â the problem is systemic.
đĄ Conclusion
- Verifiable self-custody (via own randomness, passphrase, multisig) is now the new baseline.
- This incident does not prove exchanges are safer â they have the same weaknesses but less transparency.
- Those who upgrade their setup now will hold Bitcoin in a way that is harder to break than ever before.






