It's easier than that. You simply modify the special phone to broadcast the unlock PIN being entered in realtime. You set the background to the same wallpaper as the target's phone.
You swap it physically for the target's phone on the table, netting you the target device.
Moments later, when they pick up a phone that looks just like their own and enters a PIN several times, you now have both their phone (from when you swapped it) and the PIN to unlock it (from the broadcast), allowing you full use of the device, offline, at your leisure. The target is now confused why their phone isn't unlocking, and may not detect the attack for hours.
Apple really should put these audit devices in a big, boxy, couldn't possibly-be-mistaken-for-an-iPhone case.
> The target is now confused why their phone isn't unlocking, and may not detect the attack for hours.
You might as well let the user in while you’re at it, so it’s truly undetectable.
> Apple really should put these audit devices in a big, boxy, couldn't possibly-be-mistaken-for-an-iPhone case.
Someone in Shenzhen is spinning up their CNC machine as you speak to change that to “you could probably show it to a Genius and they wouldn’t be able to tell at a glance”.
> I was thinking that the board might need to be larger, too, to make sure it couldn’t easily be transplanted.
Wouldn't that be costly from an assembly perspective? Economies of scale and all that.
Idk, this all seems much too spy-novel-esque for me. You could also install a hidden camera in the victim's room, or modify the phone to capture the video-out signal.
A scam that requires an individually targeted bespoke device that nets tens or hundreds of thousands (how does that even work? how would the proceeds be exfiltrated untraceably?) is just a really expensive way to have a very short career as a scammer.