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Can headphones transmit malware? My friend borrowed my headphones (a pair of Apple EarPods) and plugged them into his Android mobile phone for a few minutes in order to listen to a voice message. Would it be dangerous if I plug it into my phone afterwards (since I wonder whether the headphone can store malware which would eventually go into my phone)? Would it be possible to "factory reset" my headphone (just like doing so in iOS)?

  • 4
    I'd worry more about the USB port than the Bluetooth. A lot of USB devices use generalized controllers which can be reprogrammed to do more than originally intended. This usually comes into play when someone decides to do something like charge their e-Cigarette with their computer or from flash drives modified with BadUSB. – GuitarPicker Jun 15 '16 at 19:17
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    You might want to wipe the earbuds down with rubbing alcohol - that's the only possible way you could get an infection! – pericynthion Jun 15 '16 at 19:20
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    Oh yes. Earworms can be quite nasty. – user114541 Jun 15 '16 at 20:32
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    Sometimes I think this SE makes a few people paranoid. =) – jpmc26 Jun 15 '16 at 23:02
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    It's amazing to see all the brainwashing Apple has done, with all of these "OMG will Android give my Apple a virus? Android phones are so dirty!" – pipe Jun 16 '16 at 8:12

11 Answers 11

88

I doubt there is a way to store any information (thus transfer information) on regular headphones. Some more advanced models (such as noise canceling) have some processing ability and firmware, but I don't see it as a viable attack vector.

  • 14
    I bet those "need to be connected to the internet to use" Razer gaming headsets would be a great target for something like that. Also, I though noise-canceling headphones used materials to keep out other sound, not software/firmware? – WorseDoughnut Jun 15 '16 at 13:22
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    Active noise canceling actually uses a mic to listen to ambient noise and then plays the inverse sound wave into the headset, "canceling" the ambient noise. – Stephen Spencer Jun 15 '16 at 13:27
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    @StephenSpencer That is magic. – WorseDoughnut Jun 15 '16 at 13:30
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    Note that some headphones use USB to connect to a computer. – AmazingDreams Jun 15 '16 at 14:12
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    What about bluetooth headphones? Does bluetooth imply enough processing power to possibly have an attack vector? (Should this be its own question?) – durron597 Jun 15 '16 at 19:24
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While I would not say "impossible", I can say that you don't need to worry.

Headphones do not have any storage that could be used to store malware. Also, they usually do not actively send much data to the phone they are plugged into that could be used. For example, only send sound data if there is a mic, and maybe some simple play/stop/skip/volumeup/down signals. However, they do not send complex commands like "install a driver" or some other more complicated commands that could have a bug which could be exploited.

Maybe one could create a fake headphone that exploits a bug that could somehow execute something on the device. However, that won't happen on the common headphones that you or you friend have, for sure. It could be possible especially when talking about USB or bluetooth headphones, since they use a more flexible communication channel, and it is harder, but not impossible, in common jack ones - e.g. take a look in these card readers - note that for that you would need a buggy software that expects other data in the sound jack, as a card reader software, pre installed to be exploited).

As mentioned in a comment to your question, the most important thing to do when borrowing a headphone may be "wipe the earbuds down with rubbing alcohol". Other than that, don´t worry!

  • 14
    I think this is the right answer. His apple earbuds almost surely don't have the capacity to store any data so this specific scenario is not of concern. That's different than saying that no malware could be transmitted through the headphone jack. It's definitely possible to transmit data to at least some devices through the headphone jack. Someone could craft a headphones that contain malware and offer them to a target to try. – JimmyJames Jun 15 '16 at 15:17
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    Some headphones do store data, like gaming headsets that save different profiles for different games. His particular headphones most likely don't – Stephen Spencer Jun 15 '16 at 16:24
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    I know the Logitech g930 can save the light settings on the device itself, I don't know about other models though. – Stephen Spencer Jun 15 '16 at 17:22
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    To clarify, the g930 saves its per-game profiles in the computer, only the lighting profile can be saved on the device. – Stephen Spencer Jun 15 '16 at 17:39
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    For malware on a hypothetical smart headphone to attack through the headphone jack, the other device would have to already host an app to receive the data. – WGroleau Jun 16 '16 at 5:48
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Potentially, yes -- but it depends! Quite a number of Android devices (and potentially a lot of others) enable access on a serial UART console on the headphone jack during boot (a nice wrapup also exists on pentestpartners.com). You don't need a lot of electronics (and space requirements) to build a headphone that can (ab)use UART access to do something evil, from reading information to changing software.

If you're connecting headphones through USB (which will probably occur much more often with USB-C) or Apple's lightning connector, generally the same issues as with other USB devices apply -- especially if the device supports the USB host mode.

This does not fit your very special scenario where you borrow your own headphones. Somebody would have to modify the headphones and add up malicious electronics, and it does not seem your mistrust your friend to have applied something like this. But generally, headphones are a potential attack vector.

  • "modify the headphones - or, substitute a set with the modifications already made. Don't let your devices out of your sight! But, as you say, the friend here is trusted (but not the friend's device). – Toby Speight Jun 16 '16 at 17:42
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As far as I can establish, these headphones don't have memory, so they would not be able to store malware.

Also, the datastream should only be from the computer or mobile to the headphones. Even if an attacker managed to put malware on the headphones, it would be hard to send the malware to another computer or mobile.
If it were a headset (i.e. with a microphone), there would be a datastream to the device. But as long as the device has no memory, there shouldn't be a problem.

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    Some headphones/earphones are bluetooth, so it's definitely possible but rather unlikely. – AStopher Jun 16 '16 at 8:59
  • @cybermonkey Good point (+1). It goes beyond the question though, as the question is about wired use of the headphones ("plugged them into his Android mobile phone"). – S.L. Barth Jun 16 '16 at 9:07
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Something that looks like headphones and plugs into the headphone jack could be evil -- it could fry your audio chip by pushing electric current beyond normal limits. But without extra software already on the device, it can't save data to the hard drive of the device.

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No, it is not possible because a common jack cable headphone lacks 3 things that are necessary for a malware infection:

  1. Storing data
  2. Executing code
  3. Transferring data

This is something we might see coming onto headphones in the future. For example USB-headphones might come with such features which would make a malware infection and propagation possible.

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    The jack can absolutely be used to transfer data - not just audio. It just depends on what app you have running. stackoverflow.com/questions/10248649/… – dodgy_coder Jun 15 '16 at 14:17
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    +1 @dodgy_coder I remember apple had an ipod shuffle that did all its data transfer via the headphone jack. I still have the usb-to-headphone cable. Square has/had a card reader that used the audio jack for data as well – Stephen Spencer Jun 15 '16 at 15:01
  • Square card readers work through the headphone jack: d1qkpgyjx3go7e.cloudfront.net/shop/assets/products/… so I don't think this can be ignored as an attack vector. – JimmyJames Jun 15 '16 at 15:08
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    AFAIK the way data-over-headphone port works is to encode the data as an audio signal and then have software on the other side interpret it as something else. This would make an attack against Square/etc possible if you had the app installed and it was listening for data; but wouldn't allow a direct attack against the general OS. – Dan Neely Jun 15 '16 at 15:54
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    @DanNeely an attack against any software has the potential to be elevated to attack a system as a whole. – Robert Mennell Jun 15 '16 at 17:04
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Speakers and microphones are essentially the same thing: a vibrating element controlled by an electronics signal. Because of that, you can turn a speaker into a microphone quite easily by messing with the cables.

In theory, a modified headset equipped with bluetooth or a data cable (like the upcoming Lightning-connected earpieces might be) could spoof a keyboard or other connection and listen to specially crafted audio signals and transmit data directly into your phone. however, this would be a quite difficult assignment and I am unaware of any real-life attacks that use this method.

However, a standard headset or mass-produced brand of earbuds should not be able to send data to your phone.

4

No, you can't give your Android phone malware by using Apple earbuds.

Pretty much, earbuds, like any headphones, are just two small speakers each soldered to two wires that complete the circuit between the earphone and the headphone jack.

Some headphones have a volume switch, small microphone, playback control (pause/play, stop, rewind, fast forward, etc.) or a combination there of. It still would not hack into your phone unless the schematics showed anything but what was necessary for that sort of functionality.

But for your simple Apple earbuds, no it would not, and definitely should not, harm your phone.

1

The way I see it, you are asking if an Android phone infected with an Android malware could

  1. store data on your headset

  2. infect your iOS device

The first question has already been answered quite clearly.

The second however hasn't been answered. If Android code could possibly run on iOS, well a lot of programmers would be so satisfied. One could argue that the malware is capable of infecting the headphone with both compatible malware, but we know that is unlikely.

  • Cross-platform malware is entirely possible and does empirically exist. It's not necessary that the same code runs on both platforms, only that it carry attacks against both platforms. – poolie Jun 17 '16 at 19:05
  • The infected device doesn't have to be able to run the code intended for the victim device. – Micheal Johnson Jun 18 '16 at 17:05
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If they're standard headphones with an analogue audio cable, then they can't transmit malware. If they've got a digital connection such as HDMI, they can theoretically transmit malware but a vulnerability in the headphones would have to be exploited by the device transferring the malware to the headphones, and the malware on the headphones would then have to exploit a vulnerability in the devices connected later in order to infect them. If they're USB headphones, they could be reprogrammed to behave as a USB flash drive if a vulnerability in them was exploited, and USB flash drives can be used as a vector for all sorts of malware. If they've got a proprietary connector on them, you might not be able to find out what kind of data bus this connector provides and it may be possible for this to be exploited.

0

In theory

Data can be transmitted into the headphones via the audio jack or whatever connector is used. Data can be transmitted out of the headphones via the same route. If you wanted to be pedantic, data can also be transmitted out of them via the speakers themselves.

If they use USB or some other connector that's not just the standard 3.5mm audio jack, then there are definitely possible attack vectors, like executing untrusted code via the onboard USB controller, for instance. The usefulness of this method for infecting your iOS device is open for debate though.

In practice

It's highly unlikely that your friend actually deployed malware of any kind on your headphones, as the techniques described above are extremely difficult to pull off.

protected by Community Jun 17 '16 at 22:53

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