I usually try to go through a thread before commenting, but I cannot help it in this case.  I just got done doing an emergency international flight and taking care of business of a type which might be obvious to the readers of this thread.  (No losses yet that I can determine just fwiw.)

I've got a number of Coldcard Q's.  More than half have serious operational flaws (e.g., won't turn off so I use the battery as an off switch).  I suspect that the Coinkite crew are to busy with new features and devices which are much more fun and interesting than code review, QA, and going over boring documentation like how different chips and libraries (and pre-processor macros) actually work.

I have always considered the Coinkite developers to be potential enemies and only one time reached out to them for support.  Support was at best unhelpful and I retain a rather serious and costly issue with one of the devices.  Never worth my time to dig into the problem/solution, and I figured that as the months (or years) drag on, it will become more clear if I should interact with them as a serious and honest vendor, or as relatively clever and patient group of thieves.

Entropy issues have always been at the core of my concerns about any coin handling solution, and Coinkite in particular (because, to their credit, they addressed other concerns better than anyone else when I was researching things.)  Actually, the same basic issue bothers me most about Bitcoin itself.

The BTC I lost to Coldcard Q defects (and my own lack of proper system testing) were not stolen.  They sit right where they are.  If they moved, I would have known for sure that Coinkite were crooks...well...unless some defect like the one we are discussing came along...

Why didn't policymakers take precautions earlier, even though the vulnerability had already been detected—say, detected in 2021—and why are they only now realizing it? They were busy, while people's wallets, already full of accumulated BTC, were being lost. Fortunately, they were quick to detect it and immediately moved it, even though 50% of the BTC had already been lost. Otherwise, everything would have been wiped without a trace. I think it's simple: Only we know our own performance, and so does the device itself.

why did my opendimes question get deleted? cant a guy ask a question? isnt that coldcard too? jeez

I also thought about this whole thing as being an inside job. Because, why would a company neglect security alert that they know is a threat to their reputation. They knew their security was weak yet they neglected the warnings and didn't even come out publicly to warn their users. Also, they have been quiet on how to recover the coins that has been stolen, they are not providing solutions. lastly, why is it only Coldcard that is being attacked?

I believe the attacker also wish other 'self-custody wallet' have the same vulnerability like Coldcard did.
And there will be no solutions to stop the hacker on this attack, because the generated seed is already made and there's no way to revert it.
The only solution is moving the vulnerable fund to new seed.

One more thing to deny "an inside job": people outside the job also able to make an automation script to brute-force all the vulnerable seeds.
It was just a poor mistake made by their team.

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1. The tasks isn't to recover the stolen bitcoin, the tasks is to secure the bitcoin available on the "seed" that has not been stolen yet.
2. Sending the recovered bitcoins to their original address with a vulnerable seed isn't a better option at all. It is the MOST worse option.

Basically this is in-line with my preferred set of solutions, or at least a key element of one.  It remains the case, however, that you have to have enduring confidence in the entropy used to create the wallet.  Same as any other solution including Coinkite wares.

Some of the reasons I chose Coldcard Q included that the ~nvk dude had been around a while and I didn't see strong evidence of his being involved in crooked undertakings.  Of course it would be difficult to vet his employees and contractors.  They also used seemingly good hardware rng's.  Sadly, it/they were not used for the most critical cryptographic work as we would later learn.

I've a distaste for anything which uses electromagnetic radiation for comms (or dicking with uSD cards is a hassle with it's own security and usability issues.)  When I was shopping, Coldcard Q was the only device which made use of two-way QR-code interactions, and as a bonus, one could physically cut the radio options.  Mostly the device was powerful and usable for more complex work given it's form-factor, but I only appreciated that _fully_ after using it.

In my initial research I actually did find and note at least one report of Coldcard funds vanishing, and it did give me pause.  Not seeing a huge number of them I decided, with reluctance, to chalk them up to probable user-error, competitor FUD, or some such.  Now it looks more like proof-of-concept and getting a little spending money by someone somewhere.  If Coinkite really did ignore and bury the complaints, that is not at all a good look.

I am hopeful that in order to make amends to the community, Coinkite donates the whole Coldcard Q effort, including supply chain info, to the community.  Code development _INCLUDING TESTING_, profiling, distribution, etc might then be able to be done by people who have a wider range of skills and interests.  It would be great if such firmware would be distributed with a bootstrapped environment (compilers, test harnesses, etc) which may foster more interest among users to undertake more complex tasks.

The Silver Lining - At least ColdCard didn't sell as much hardware devices as Trezor or Ledger. If ColdCard was the most successful hardware wallet that sold devices to millions of users, I'm very confident that the current situation would be more like the FTX crash or the Terra Luna crash.

The community in general is still "lucky" that the stupidity came from the ColdCard developers.

The Bitcoin Policy Institute created a visual overview of the Coldcard vulnerability, comparing seed phrases to atoms. In their video they describe a properly generated seed as an atom hidden somewhere across two billion galaxies, impossible to find by any computer/AI. Compared to that huge space, Coldcard's seed generation is presented as one atom in a virus. A computer could find it in a few hours. It's an interesting watch, so take a look:

https://www.youtube.com/watch?v=IwrKWdxt0YM


One person found a new use case for his Coldcard Q. He created a game, The Bitcoin Dungeon. You run around the different levels, collecting bitcoin and staying away from bankers. It's not meant to make fun of the victims that lost their coins. It just shows what's possible.


https://x.com/pastorcoin/status/2084438312803090648

Honestly the concern is justified, attack area has grown by leaps and bounds and what was once considered safe two years ago is no longer safe.
SeedSigner is good option for Bitcoin in particular. Open source, air gapped, parts cost around $50, and community guides are good enough that technically curious person could make one without too much trouble. With no company owned software, there is no need to blindly trust maker code.
You should be able to follow build process easily, as you have some experience with it. Could be a good time to finally take that shot.