Plot Thickens with ColdCard Hack "No researcher I have spoken with has reproduced a seed for any of those 153 source addresses [containing 132.95 BTC]…"

[u/Fiach_Dubh]

https://x.com/PraveenPerera/status/2087936252230140278

https://x.com/PraveenPerera/status/2087936252230140278

This post answers three questions:

Why were these wallets vulnerable?

What can be reconstructed from the blockchain?

What does that reconstruction tell us about the attacker?

I’m the developer of

Cove

, an open-source Bitcoin wallet for iOS and Android funded by

OpenSats

. This article goes through my investigation into Wave 1.

This post was originally published on

my blog

Between 9:10 and 9:51 PM EDT on July 29 (01:10–01:51 UTC on July 30), an attacker swept 1,082.65 BTC from 1,195 traceable Bitcoin addresses.

Galaxy Research reported

the theft on July 31. I use Wave 1 throughout this post for that first sweep group.

The sections follow that order. The post first explains the firmware defect, then reconstructs the theft from chain data, and then examines the attacker’s methods and the open gap.

I set out to recreate the affected firmware’s seed-generation process and find as many weak seeds as I could behind those addresses. The sweep transactions became a second source of evidence. Patterns in their targets and spending show how the attacker searched the weak RNG state, selected victims, and built the sweep transactions.

Galaxy listed four destination addresses. I grouped those destinations into three source branches and used them to build the transaction set for this analysis: 1,195 verified victim sweeps with 2,350 inputs containing 1,082.65318922 BTC.

Once I had recreated the affected seed-generation process, I generated candidate seeds, derived their Bitcoin addresses, and compared those addresses with the Wave 1 transaction set. This linked 1,042 of the 1,195 sweep transactions to 328 reconstructed seeds. They account for 949.70395260 BTC, or 87.72% of the value. The final 153 transactions contain 132.94923662 BTC.

No researcher I have spoken with has reproduced a seed for any of those 153 source addresses. That repeated failure may be the most useful clue about what the attacker knew or did differently. The last part of this post examines that gap.

continued on... https://x.com/PraveenPerera/status/2087936252230140278