BusKill – A USB kill cord for laptops • Hacker News Board

Re: BusKill – A USB kill cord for laptops

#151

Post by pmorici » Wed, Dec 15, 2021, 2:59 PM UTC

zionic wrote: post #102

yholio wrote: post #77

Good to have if you run a dark net marketplace or a political disident ring from public libraries. An additional refinement is to autolock the device if a certain personal key combo (ex. Shit - vol up - vol down) is not pressed every few minutes in response to an audible click. If not unlocked in a minute or so with a complex password, the device halts to a disk encrypted state and unpowered ram, minimizing the windo…

Wouldn't it make sense to remove the battery on your laptop entirely? With a modified magsafe-like power cord any attempt to grab the machine hard-kills the system and RAM begins degrading immediately. Epoxy over the screw terminals would also delay an attacker long enough to prevent freezing the RAM with compressed air to try and dump RAM via an exploit kit.

Devices to transfer from wall power to battery backup for transport have existed for a long time.

https://wiebetech.com/products/hotplug-field-kit/

Re: BusKill – A USB kill cord for laptops

#152

Post by reaperducer » Wed, Dec 15, 2021, 3:00 PM UTC

MayeulC wrote: post #124

Jerrrry wrote: post #98

Earlier quoted context omitted.

Instead of a personal key combo, a dongle with an OTP code. Both the dongle and the computer have accelerometer-bump-tilt-oh-fuck-support. A OTP has to be entered every 5 minutes, or a secure screen/dead sequence starts. Sudden accelerated movements or a lack of presence-detection would also start the sequence.

I once wrote a script to automatically lock my computer if I got too far away from it, back when I was wearing a bluetooth wristband. I guess you could do the same, but shut down the computer instead.

I once wrote a script to automatically lock my computer if I got too far away from it, back when I was wearing a bluetooth wristband.

I had a program like this back in PowerBook days. It automatically unlocked the computer if a specified Bluetooth signal reached a particular strength, and locked the computer again if the signal strength fell below another threshold.

It worked great, when it worked. It had maybe a 70% success rate, but that was good enough.

Re: BusKill – A USB kill cord for laptops

#153

Post by captaincrunch » Wed, Dec 15, 2021, 3:01 PM UTC

What would stop someone from crazy gluing the easy release cable, shaving the wire back and connecting power to the usb before removing it?

Re: BusKill – A USB kill cord for laptops

#154

Post by aydwi » Wed, Dec 15, 2021, 3:04 PM UTC

WesolyKubeczek wrote: post #141

Say I'm an investigative journalist, gathering information about some bad guy embezzling all politicians that matter in a small country and doing all kinds of criminal stuff, including murders. I'm careful. I'm using a laptop that has this kill switch. I only keep my work on this laptop, it's so sensitive. The bad guy gets a whiff I'm digging around him. He sends armed thugs to my lair. They enter, so I pop the kill…

You joke but this might have happened already

Re: BusKill – A USB kill cord for laptops

#155

Post by FearlessNebula » Wed, Dec 15, 2021, 3:05 PM UTC

323 wrote: post #79

mmaunder wrote: post #38

Might have protected Ross Ulbricht, but he’s an edge case. Anyone had their laptop yanked away while using it?

Actually we know it wouldn't. The agents arresting him did in such a way that they prevented him from touching his laptop (by creating a diversion), because they were feared that such a protection might exist.

What if he clipped it to his belt?

Re: BusKill – A USB kill cord for laptops

#156

Post by FearlessNebula » Wed, Dec 15, 2021, 3:06 PM UTC

Hamuko wrote: post #138

zionic wrote: post #107

Earlier quoted context omitted.

If done properly the agents grabbing his laptop/snatching it away from him would have severed the power connection to the battery-remove laptop locking it permanently.

> If done properly The man was running a multi-million dollar drug marketplace in a public library.

What was the logic behind that? So he couldn’t be traced back to his house?

Re: BusKill – A USB kill cord for laptops

#157

Post by captaincrunch » Wed, Dec 15, 2021, 3:06 PM UTC

tbabej wrote: post #7

For the Yubikey owners out there, a while back I wrote a blog post on how to achieve a similar setup using a Yubikey [1]. All it requires is a lanyard to attach the yubikey to. [1]: https://tbabej.com/Yubikey-secure-session-setup/

Anyone needing a Yubikey would be very lucky to see them just hanging out of a computer, would just a bonus for the evil actor to also ruin your day and pull it out.

Re: BusKill – A USB kill cord for laptops

#158

Post by MayeulC » Wed, Dec 15, 2021, 3:07 PM UTC

nefitty wrote: post #137

MayeulC wrote: post #124

Earlier quoted context omitted.

I once wrote a script to automatically lock my computer if I got too far away from it, back when I was wearing a bluetooth wristband. I guess you could do the same, but shut down the computer instead.

Unfortunately, iOS-provided location resolution for use in shortcuts makes it worthless for in-home use. Unless you live in a mansion though I guess.

You are assuming the signal is strong enough to be read at a distance. I just used the RSSI, and going away a few meters was enough. Moreover, since that was just a nicety in case I forgot to lock my computer during a corridor conversation, I could get away with a longer timeout.

A more sophisticated implementation could be done if you can write software on the device. A PineTime would be perfect for this.

I am not sure why mention iOS specifically, a phone is easily forgettable. Moreover, you don't really need to rely on any location API provided by the system, even if UWB or Bluetooth Location Services would do wonders for this, a simple RTT latency measurement or RSSI value should be enough.

Re: BusKill – A USB kill cord for laptops

#159

Post by FpUser » Wed, Dec 15, 2021, 3:08 PM UTC

yholio wrote: post #77

Good to have if you run a dark net marketplace or a political disident ring from public libraries. An additional refinement is to autolock the device if a certain personal key combo (ex. Shit - vol up - vol down) is not pressed every few minutes in response to an audible click. If not unlocked in a minute or so with a complex password, the device halts to a disk encrypted state and unpowered ram, minimizing the windo…

Tried to find "Shit" key on my keyboard as it would save me a lot of time. No luck.

Re: BusKill – A USB kill cord for laptops

#160

Post by kingcharles » Wed, Dec 15, 2021, 3:09 PM UTC

yholio wrote: post #77

Good to have if you run a dark net marketplace or a political disident ring from public libraries. An additional refinement is to autolock the device if a certain personal key combo (ex. Shit - vol up - vol down) is not pressed every few minutes in response to an audible click. If not unlocked in a minute or so with a complex password, the device halts to a disk encrypted state and unpowered ram, minimizing the windo…

Exactly. You need something not for when your laptop is removed from you, but when you are removed from your laptop.

Also, if you are being targeted this hard you need to have something for when you are left in front of your laptop and a gun is put to your head. Or the attackers threaten the welfare of your family.