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How I discovered a hidden microphone on a Chinese NanoKVM

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Re: How I discovered a hidden microphone on a Chinese NanoKVM

#31

Post by f1shy »

mystraline wrote: post #22
nottorp wrote: post #18

Earlier quoted context omitted.

Let's see: 1. It lacks systemd and apt. systemd is so resource hungry that i'm sure they removed it to reduce the RAM bill. Apt... why install apt if the distro has a different means of updating? 2. While these are useful for debugging and development, they are also hacking tools that can be dangerously exploited. This is purely fear mongering. Even the shell could be a "hacking tool that can be dangerously exploited…

Cat is a hacking tool cause you can see the contents of /proc/kcore? Cp is a hacktool cause bad files can be copied? Grep is a hacktool cause only monster hackers use regex? (This is obvious sarcasm)

Heck, everybody knows Linux is a hacker OS…

Re: How I discovered a hidden microphone on a Chinese NanoKVM

#32

Post by CoastalCoder »

jlward4th wrote: post #11

I recently discovered a similar concerning security issue with my KVM. In my case it was a pretty standard KVM for multiple machines to share a keyboard, mouse, and screen but also Ethernet. One day while looking at my home network I noticed the KVM had its own IP and was transferring GBs of data everyday. I quickly blocked it from my network. But having used it for a number of months I worried that with screen captu…

Is it possible for you to name the KVM model?

It sounds like a potential risk is to the public.

Re: How I discovered a hidden microphone on a Chinese NanoKVM

#33

Post by gunalx »

I dont see the issue here. Its not like they have not disclosed what board it is based upon. And I do feel like its correct not advertising a mic if you dont have it enabled on this one.

I dont really like nanokvm for being slow with updates and not patching stuff fast enough.

Re: How I discovered a hidden microphone on a Chinese NanoKVM

#34

Post by cdaringe »

Y_Y wrote: post #23
Workaccount2 wrote: post #12

Earlier quoted context omitted.

No, because the drive circuit for a speaker is the opposite of the circuit for a microphone. The output stage of a speaker amplifier is just that, an output . The only way to record audio from a speaker, which is totally possible, is to have also purposely built an input stage also attached to the speaker. Which at that point you might as well just use a microphone... Audio input and output are not reversible.

I don't know what you mean here, I can plug a speaker into my mic slot and use that to record, just as plugging a mic into the speaker slot gives a (crappy) speaker.

> purposely built input stage

You moved your device to the purposely built input stage.

Not an expert, but your remark doesn’t compute with the parent comment

Re: How I discovered a hidden microphone on a Chinese NanoKVM

#35

Post by ndsipa_pomu »

Y_Y wrote: post #21
ndsipa_pomu wrote: post #13

Earlier quoted context omitted.

It doesn't strike me as that useful to have a hidden microphone in a KVM product as most of the time, they're going to be stuck in server rooms with just lots of fan noise to record. Far more of an issue would be any kind of keylogger built into the software, which is why it's best to go for devices that support open source software.

just fan noise? https://arxiv.org/abs/1606.05915 Any signal that you can modulate can be an exfiltration channel, and fan noise is no different.

I wonder if that's feasible in a room filled with many servers and fans going?

Re: How I discovered a hidden microphone on a Chinese NanoKVM

#36

Post by pirbull »

> You can start with your iPhone - last year Apple has agreed to pay $95 million to settle a lawsuit alleging that its voice assistant Siri recorded private conversations. They shared the data with third parties and used them for targeted ads. “Unintentionally”, of course! Yes, that Apple, that cares about your privacy so much

the clickbait title makes sense after reading this paragraph

Re: How I discovered a hidden microphone on a Chinese NanoKVM

#37

Post by nottorp »

f1shy wrote: post #31
mystraline wrote: post #22

Earlier quoted context omitted.

Cat is a hacking tool cause you can see the contents of /proc/kcore? Cp is a hacktool cause bad files can be copied? Grep is a hacktool cause only monster hackers use regex? (This is obvious sarcasm)

Heck, everybody knows Linux is a hacker OS…

Hey I didn't think of that. They forgot to complain that the device doesn't use a properly licensed OS that they certified secure!

Absolutely with systemd and apt. Like apt couldn't be used to install "hacking tools".

Re: How I discovered a hidden microphone on a Chinese NanoKVM

#40

Post by ErroneousBosh »

f1shy wrote: post #30
ErroneousBosh wrote: post #24

Earlier quoted context omitted.

A long time ago (maybe in the mid-90s) I knew an elderly radio amateur who could not just "copy" CW by ear, but also RTTY. He could also pretty much tell what a teleprinter was printing just by listening to the noises it made, like he'd be facing away from it on the other side of the room reading out entire words from what was coming through. Apparently in the 50s when he did his National Service he'd been in the Sig…

Do you have a pointer to learn more about the ATM keyboards? I would love to learn more about it

Maybe. They were necessarily very cagey about it back then, but I might have some documentation kicking about in storage. I tended to keep copies of every service manual I could get my hands on back then.
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