

Most systems provide some sort of brief alert tone, but this is entirely implementation based. That is to say, the phone never rings the audio channel just opens. Executive barge in allows a user with the appropriate rights to open an audio channel to any phone connected to the switch, bypassing the alerting phase. There's a feature called "executive barge in" that pops up from time to time when shopping for PBX systems. Working in telecom was enlightening for me. Cell phones are eminently more susceptible to this type of attack because the government can compel carriers to use technology that is already in place.

If you're after a specific individual, a far better target than their computer would be their cell phone. Now Poe's Law kicks in and I can hear headlines already "Apple removed the line-in on purpose to spy on us!" and since line-in disappeared but the (HDA or whatever) sound chip certainly still has this functionality, what would prevent Apple from having a second microphone plugged into that line-in, completely hidden and uncontrollable?
PHYSICAL MICROPHONE FOR MACBOOK CODE
but if it's not external code it has to be internal (i.e Apple provided), so what would prevent Apple to simply tell you it's off when it would not actually be?
PHYSICAL MICROPHONE FOR MACBOOK DRIVERS
so if it's external code injected by a malicious guy, what prevents him from setting it back to internal (and setting it back to line-in when you're looking)? Or craft all sorts of drivers hooking into or replacing AppleHDA.kext or whatever?

what would listen to it if it was on? necessarily some code, or else it just goes straight to /dev/null. And as soon as an app opens it, it turns back on.Įven then, let's assume the sound card is always on (like my old SB16): It's on when the prefpane is shown for the purpose of displaying that VU meter but as soon as you quit the prefpane, the hardware turns off. In fact the sound card even powers itself down when not in use, which can actually be heard in some cases (with some badly shielded/grounded HP for example). Actually I don't think it is listening at all when not in use.
