5 ms·

So we assume that an adversary has dropped some malware that can silently enable the radio, activate the microphone, encode the audio stream and transmit it in

So we assume that an adversary has dropped some malware that can silently enable the radio, activate the microphone, encode the audio stream and transmit it in real-time - and they want to avoid detection by this case. Well, all they need to do is modify the malware to record the audio to a file and transmit it when the radio is next switched on, perhaps interleaving it with normal radio activity. As a malware detector, this case is useless.

toyg 10y ago
They would have to know the exact meeting time and would use space on the device, which could be noticed. This case is not a silver bullet, but it's a useful tool.
- tablehampton 10y ago
  Or they could record to file only when the radio is off, and transmit directly without recording when it is on.
ddt_Osprey 10y ago
Not useless. Just less useful. It pushes the capacity for your adversary to operate into (slightly) slimmer confines, which is a marginal improvement. Otherwise, your adversary can behave in an unrestrained manner. No?
- chakalakasp 10y ago
  I guess. For the kinds of clients who would want this device, this would just be like making it so that you're only a little bit pregnant. You either prevent the eavesdropping or you don't. The only safe tactic is not bring the device anywhere you don't want to be tracked or recorded. Or to technologically prevent it from operating somehow in a way that doesn't rely on verification -- such as taking the battery out, if you can, or putting it in a verified faraday cage that you keep in a soundproof box if you can't. And if you're the kind of person with a life so interesting they need to worry about about phone implants, maybe take battery removability into consideration when you buy the device.
- tedunangst 10y ago
  One might also argue that giving a violent prisoner left-handed scissors will slow them down and is therefore a marginal improvement.
  - burzum 10y ago
    At least, if you're dealing with someone, and you notice that they have one of these, it's a signal that they'd probably be open to parting ways with their device for a period of time, while something else takes place. Without the display of this sort of status symbol (all cellular phones and mobile devices are status symbols), you have neither floor nor ceiling, regarding level of electronic paranoia.
  - sangnoir 10y ago
    I can't argue with that: if I had to choose between the two, I'd rather be stabbed by the non-dominant hand. Obviously not being stabbed at all is a much better choice (when available).
deadbunny 10y ago
That was my immediate thought, if they have access to your phone at that level recording (voice, packets, gps co-ords) to a file then sending it once it has signal would be trivial. It would provide a misguided level of confidence in their security which could lead to exactly the consequences trying to be avoided. Got a secret meeting? Don't take your bloody phone.
- mentat 10y ago
  Of course not taking your phone is a visible data footprint if you're detected in other ways. Secrecy is a pretty hard problem now.
  - philipov 10y ago
    The objective, in this case, is to prevent recording of the proceedings, not keep the very existence of the meeting a secret.
Zigurd 10y ago
It has been confirmed that some mobile basebands are, in fact, remotely controllable even when a device is apparently off. It isn't a far-fetched scenario. http://www.seattletimes.com/nation-world/even-if-theyre-off-cellphones-allow-fbi-to-listen-in/ http://www.seattletimes.com/nation-world/even-if-theyre-off-... In this case it was a Motorola device on an iDEN network, probably using a Freescale baseband. But it is likely that most major vendors were persuaded to include similar capabilities and that network providers cooperate in providing special signaling to control these capabilities.
BurningFrog 10y ago
That a security measure is not impossible to defeat does not mean it's useless.
robryk 10y ago
This also detects when the GPS is used. If the phone has GPS and cell radio (for reception and transmission) disabled, it's a lot harder for any malware to figure out its location (not impossible -- there is some research about identifying locations in a metro network using an accelerometer alone). While it's easy to prevent the phone from recording your conversation (just place it somewhere out of earshot, maybe next to a noise source for the duration of the conversation alone), it's much harder to prevent it from learning where you're going (if you're taking it with you).
mSparks 10y ago
Baseband processors in all mobiles have direct access to the microphone and it is fairly trivial to access remotely. Comes as standard on all stingray devices available to any and all perverts willing to use it. Only Samsung devices have been shown to give the baseband processor backdoor access to device storage. Afaik.

toyg 10y ago

They would have to know the exact meeting time and would use space on the device, which could be noticed. This case is not a silver bullet, but it's a useful tool.

tablehampton 10y ago
Or they could record to file only when the radio is off, and transmit directly without recording when it is on.

ddt_Osprey 10y ago

Not useless. Just less useful. It pushes the capacity for your adversary to operate into (slightly) slimmer confines, which is a marginal improvement. Otherwise, your adversary can behave in an unrestrained manner. No?

chakalakasp 10y ago
I guess. For the kinds of clients who would want this device, this would just be like making it so that you're only a little bit pregnant. You either prevent the eavesdropping or you don't. The only safe tactic is not bring the device anywhere you don't want to be tracked or recorded. Or to technologically prevent it from operating somehow in a way that doesn't rely on verification -- such as taking the battery out, if you can, or putting it in a verified faraday cage that you keep in a soundproof box if you can't. And if you're the kind of person with a life so interesting they need to worry about about phone implants, maybe take battery removability into consideration when you buy the device.
tedunangst 10y ago
One might also argue that giving a violent prisoner left-handed scissors will slow them down and is therefore a marginal improvement.
- burzum 10y ago
  At least, if you're dealing with someone, and you notice that they have one of these, it's a signal that they'd probably be open to parting ways with their device for a period of time, while something else takes place. Without the display of this sort of status symbol (all cellular phones and mobile devices are status symbols), you have neither floor nor ceiling, regarding level of electronic paranoia.
- sangnoir 10y ago
  I can't argue with that: if I had to choose between the two, I'd rather be stabbed by the non-dominant hand. Obviously not being stabbed at all is a much better choice (when available).

deadbunny 10y ago

That was my immediate thought, if they have access to your phone at that level recording (voice, packets, gps co-ords) to a file then sending it once it has signal would be trivial. It would provide a misguided level of confidence in their security which could lead to exactly the consequences trying to be avoided. Got a secret meeting? Don't take your bloody phone.

mentat 10y ago
Of course not taking your phone is a visible data footprint if you're detected in other ways. Secrecy is a pretty hard problem now.
- philipov 10y ago
  The objective, in this case, is to prevent recording of the proceedings, not keep the very existence of the meeting a secret.

Zigurd 10y ago

It has been confirmed that some mobile basebands are, in fact, remotely controllable even when a device is apparently off. It isn't a far-fetched scenario. http://www.seattletimes.com/nation-world/even-if-theyre-off-cellphones-allow-fbi-to-listen-in/ http://www.seattletimes.com/nation-world/even-if-theyre-off-... In this case it was a Motorola device on an iDEN network, probably using a Freescale baseband. But it is likely that most major vendors were persuaded to include similar capabilities and that network providers cooperate in providing special signaling to control these capabilities.

BurningFrog 10y ago

That a security measure is not impossible to defeat does not mean it's useless.

robryk 10y ago

This also detects when the GPS is used. If the phone has GPS and cell radio (for reception and transmission) disabled, it's a lot harder for any malware to figure out its location (not impossible -- there is some research about identifying locations in a metro network using an accelerometer alone). While it's easy to prevent the phone from recording your conversation (just place it somewhere out of earshot, maybe next to a noise source for the duration of the conversation alone), it's much harder to prevent it from learning where you're going (if you're taking it with you).

mSparks 10y ago

Baseband processors in all mobiles have direct access to the microphone and it is fairly trivial to access remotely. Comes as standard on all stingray devices available to any and all perverts willing to use it. Only Samsung devices have been shown to give the baseband processor backdoor access to device storage. Afaik.