i've installed Graphene on a 6a recently and I update it via Ethernet only. the other day, i installed the app "skewy" from f-droid on another phone and was experimenting if it pics up inaudible signals in my home. i've noticed that my ps4 is sending coded signals at certain intervals, most notably while saving the game state. i wasn't surprised at all, although i keep it off the internet entirely.

however, i laid that phone next to my now graphene os driven pixel 6a and noticed that the moment i started an update, the 6a unfortunately produced coded signals at around 19 kHz for a certain time and it showed up in my skewy app, which sounded alarms every other second.

did anyone else experience this? i've hooked the phone up for another update and did the same thing, although this time there were no signals detected. i might add, i had disabled the mic on the 6a since the signal detection. to be clear, i hadn't used any (public or private) wifi on the 6a and i don't use wifi at home with my own router either, it is permanently disabled.

is the 6a compromised?

adding to that, the skewy app is quite interesting. i've tested it with my speakers at home and produced a filter swipe from 14kHz to 20kHz and it did pick up the frequencies respectively.

i have somewhat of a reason to assume that my 6a might be compromised bc of a certain geographically sensitive region i've been to recently. so it wouldn't come as a surprise either. i suppose i have to wipe and install from scratch at this point? unless, the graphene os produces jamming frequencies and all that was basically some kind of internal function. does anyone know?

  • de0u replied to this.

    umbrin688 Not all ultrasonic emissions are "coded" -- some are noise. Various internal components of modern electronic devices, including screens, touch sensors, and DC-to-DC converters, make noise, and they are generally engineered to make the noise outside of the normal range of human hearing.

    If you reboot your Pixel and it shows the correct signature hash then the OS very likely has not been compromised. What applications installed on the device are doing in terms of audio is up to them.

        de0u so

        de0u how do we know what the correct signature hash is? And why does this mean it very likely hasn't been compromised?

        • de0u replied to this.

              thx for the replies! i stuck to the advice not to install any unnecessary apps and as few as possible. so my only apps are Signal and OSMR maps.

              anyhow, @de0u was probably right. i did realize that my stereo speakers, even when turned off, emit noise at around the same frequency. there's still a bit of doubt, as i tested the amplitude of the signal by walking away from the 6a with my skewy app phone and approached it again, holding it very close to the 6a. the signal did get louder on coming nearer although said speakers were on the very other end of the room.

              i will check the signature hash. i have no other device that can install the auditor app, so that's not possible rn.

                10 days later