Having one of those small adapters is nice. But people are people, and people forget things.
If I drop a few of those cables around a show like BlackHat or Defcon probably nobody is going to plug them into anything.
Leave a few around Bitcoin Miami and you could probably get someone to plug them in.
Buy a few dozen (yes it's expensive) but then put a logo on for something that looks like a giveaway and you know people are going to use it....
You'd be surprised how often you do find USB freebies at conferences such as BlackHat and similar.
Infecting PCs using free USB devices is a very common practice and even part of the toolbelt of lots of professional pentesting companies.
Until now, I was under the impression that if you only transmit PSBTs through USB, a simple corrupting / replacing attack would definitely lead to the wrong address showing on the hardware device's screen.
I'm very excited to see how you're going to circumvent this for hacking USB hardware wallets, though!
It will do those easier if it's just putting in an address. It's actually trivial.
Remember it not just a key logger, it can also run apps and put stuff into the PC.
So if he can get to the page inspector in chrome (or whatever it is in that particular browser) he can modify a
BTC address at a known location. Since it's always in the same space here:
https://bitcointalk.org/index.php?action=credit;promote it's a known spot in code that can change to his address. For now it can only change the address QR codes cannot be done (yet)
From this text it appears to me that you're just replacing the address shown on screen with a malicious one as well as sending that address to the hardware device; thus the user sees the same one on both devices. That's quite smart and should be relatively simple to do, sounds good to me!
The trick with the HW wallet is that it's breaking the encryption loop with their app.
I don't understand this however. You're breaking encryption now? Why?