why stupid things like the usb-killer do exist?

[legacy]

it's specifically designed to destroy computers and smartphones: does it make sense?
more interesting, some devices may survive, the most won't 

which is the best protection (apart from not allowing people to plug anything on the usb slot)?

[coppercone2]

well if it makes you feel better, you can do serious time for destroying computers.. quite a dollar value attached to them and its probably considered worse then theft from a judges view point.

Protection can be tricky because you need to maintain a low capacitance to maintain usb SNR, high speed and high voltage.

[coppercone2]

https://hardware.slashdot.org/story/19/04/17/2120206/student-used-usb-killer-device-to-destroy-58000-worth-of-college-computers

Vishwanath Akuthota, the former student, now faces up to 10 years in prison (with up to three years of supervision after release) and a fine totaling up to $250,000.

Whats a bit scary is that normally to do that kind of damage, you would need to get pretty winded with a sledge hammer for a good 20 minutes.

[daqq]

it's specifically desiend to destroy computers and smartphones: does it make sense?

Yes. The simple answer is that some people are dicks and just want to see the world burn. There are also other uses, sabotage, economic malice etc. pretty much all illegal. Basically a single bribed cleaner, maid, janitor or similar can take down a company.

which is the best protection (apart from not allowing people to plug anything on the usb slot)?

Isolated, heavily protected USB hub, that can die, but will not pass the destruction further. Non-stupid people.

Beyond that I don't think that there are any (reasonable) protections that can stand continued battering from such a source and at the same time pass USB data.

[OwO]

Optical USB isolator.

[Halcyon]

Surprisingly, quite a few modern smart phones can withstand it such as the Samsung phones.

[soldar]

The simple answer is that some people are dicks and just want to see the world burn.

Human nature is pretty much the same everywhere. People like power and that feeling of power can be obtained by destroying things and/or people.

It takes a lot of hard work and preparation to feel the satisfaction of having built a building or a machine or an airplane and young people are not there yet but they can feel the satisfaction of having destroyed what took someone else a lot of work to build.

You can take a few young men and put them in a fighter jet or in the army and make their thirst for destruction legal and virtuous but in nature it is no different from the neighborhood punk who goes around keying cars.

The guy who creates a computer virus just for fun is not much different from the guy who works for a big government and creates a virus useful to their government. The legality and consequences are very different but the motivation is not.

A keeper is only a poacher turned outside in,  and a poacher a keeper turned inside out.  Charles Kingsley - 19th century

I have met a lot of people in places of authority who were just assholes backed by authority but were worthless human beings abusing whoever they could. If they were not in positions of authority they would probably be doing the same things outside the law.

[Gyro]

If you do a forum search for 'USB killer' you will find that this topic has come up several times in the past (not for a while though). As far as I remember, nobody ever came up with a satisfactory reason / excuse.

[NiHaoMike]

"Sanitizing" public chargers is one of the few legitimate uses. The idea being that they're supposed to just have the data lines tied to each other and therefore immune to high voltage, but if some hacker installs a device that tries to hack connected devices, that hacking device would be disabled and rendered harmless.

[ElectronicSupersonic]

People do stupid things. In many cases unintentionally, but sometimes stupid things are done very much intentionally/deliberately. 

Unintentional stupidity is more dangerous, then intentional (IMHO), since it's harder to predict.

[m98]

"Sanitizing" public chargers is one of the few legitimate uses. The idea being that they're supposed to just have the data lines tied to each other and therefore immune to high voltage, but if some hacker installs a device that tries to hack connected devices, that hacking device would be disabled and rendered harmless.

But then you're also killing all USB power delivery compatible chargers...
Using this device on something else than your own property is vandalism. If you want to safely charge your phone, just use a cable without the data lines.

[Zbig]

"Sanitizing" public chargers is one of the few legitimate uses. The idea being that they're supposed to just have the data lines tied to each other and therefore immune to high voltage, but if some hacker installs a device that tries to hack connected devices, that hacking device would be disabled and rendered harmless.

But then you're also killing all USB power delivery compatible chargers...
Using this device on something else than your own property is vandalism. If you want to safely charge your phone, just use a cable without the data lines.

Exactly. Also, USB charging is a hot mess and before the actual, approved standards like USB PD, USB DCP were a thing, there were - and still are - countless others that rely on probing the data lines. Some of them expect shorted data lines, others some arbitrary resistance, others some timed sequencing, others still - various combinations of pull-ups/and/or-downs to +5V, GND. Various versions of QuickCharge involve actual voltage negotiation using signaling over data lines. More advanced chargers have purpose-designed chips that try to guess what the device to be charged expects by "listening" to their probing routine and playing along accordingly (e.g. "IQ Charge").

If I were an honest owner of a property that offers their guests USB charging ports for their convenience and caught you trying to "sanitize" them using high-voltage crap gizmo, I'd "sanitize" you by making you eat the damn thing.

[NiHaoMike]

But then you're also killing all USB power delivery compatible chargers...
Using this device on something else than your own property is vandalism. If you want to safely charge your phone, just use a cable without the data lines.

It could be used by the owner of the public charger. Although I suppose a better way to counterattack those hacked public chargers is to plug in a device that pretends to contain valuable data but is actually worthless junk designed to waste the resources of the hacking device.

[Zbig]

It could be used by the owner of the public charger. Although I suppose a better way to counterattack those hacked public chargers is to plug in a device that pretends to contain valuable data but is actually worthless junk designed to waste the resources of the hacking device.

What "counterattacks" are you on about? You're not on a freaking war. If you see hackers everywhere you always can, you know, NOT try to freeload on the public chargers, perhaps? Carry your own powerbank or just deal with not having a charged smartphone, FFS

[NiHaoMike]

What "counterattacks" are you on about? You're not on a freaking war. If you see hackers everywhere you always can, you know, NOT try to freeload on the public chargers, perhaps? Carry your own powerbank or just deal with not having a charged smartphone, FFS

I suspect "hacked" public chargers are very uncommon, but owners of those chargers do need some way to counter that problem. Maybe the manufacturer of the public charger can specifically design it to be "sanitized", with a modified connector that will accept either a standard USB plug or the "sanitizer" that the manufacturer supplies, but prevent accidentally plugging the sanitizer into a USB port not designed to handle it.

[//Matt//]

It's basic purpose is to make you feel better by destroying other peoples private property. Yo can also destroy our own property and make a viral video out of it.
 

[Nominal Animal]

It is the equivalent of pouring sugar in a fuel tank, except that there are people who think fuel tanks USB ports should be protected against that.
(And, like fuel tank caps, USB and Ethernet ports should be physically protected against use by idiots and vandals and other vermin.)

Before USB, there was the Etherkiller: An RJ45 on one end, and a mains plug in the other, BOFH style.

The one sensible use for one (USB or Ethernet killer) I can think of, is as destructive test gear when you are developing something to allow interfacing possibly nefarious devices.  (For USB, that means limiting the types of USB devices that are enumerated, to e.g. storage devices, and possibly keyboard devices if you wish to allow password keepers.  For Ethernet, robust magnetics and a design that keeps damage to within the single port.)

I'm pretty sure you could do a Mainskiller also, maybe using some clever power circuitry to double the AC frequency or something.  It'd be the same thing, really, just even more dangerous and destructive.

[tszaboo]

Because we humans are like that.
"And if you gaze long into an abyss, the abyss also gazes into you" kinda deal.
I mean it's not like someone intentionally setting Rome on fire.

[magic]

I once considered building it for my roommate who kept borrowing my USB device without asking and generally was an ass in many ways but I still had too much pity.

[NiHaoMike]

I'm pretty sure you could do a Mainskiller also, maybe using some clever power circuitry to double the AC frequency or something.  It'd be the same thing, really, just even more dangerous and destructive.

Just need a sufficiently large high voltage capacitor. It really would be big, though, given any decent surge protector is rated for several thousand joules. Easier to just put in a transformer to make a high current flow through the neutral to ground loop.

[langwadt]

https://hardware.slashdot.org/story/19/04/17/2120206/student-used-usb-killer-device-to-destroy-58000-worth-of-college-computers

Vishwanath Akuthota, the former student, now faces up to 10 years in prison (with up to three years of supervision after release) and a fine totaling up to $250,000.

Whats a bit scary is that normally to do that kind of damage, you would need to get pretty winded with a sledge hammer for a good 20 minutes.

not going to defend the guy but, 10 years in prison and a $250,000 fine is beyond insane

[magic]

not going to defend the guy but, 10 years in prison and a $250,000 fine is beyond insane

As is deliberately destroying multiple college computers. Play stupid games, win stupid prizes.
Besides, it was "faces up to 10 years", which only means they found enough paragraphs to theoretically be able to lock him up for that long.

[langwadt]

not going to defend the guy but, 10 years in prison and a $250,000 fine is beyond insane

As is deliberately destroying multiple college computers. Play stupid games, win stupid prizes.
Besides, it was "faces up to 10 years", which only means they found enough paragraphs to theoretically be able to lock him up for that long.

computers are easily replaced, it's not like he killed someone. spending millions to store him in a cell for a decade after which he will
never get a job or pay taxes seems like and excessively stupid way to handle it and cause much more damage than the initial crime

it does seem like US justice system is to busy to argue in court so they pile up charges until they convince the criminal to
make a plea bargain ( or kill themselves ) to avoid a life sentence

[bd139]

They have a legitimate use which is basically destroying your kit and the TPM in and crypto keys irrecoverably and permanently. No amount of fancy shit down the lab can fix the damage it does. Think journalists, spies, activists, data exfiltration protection, hardware sanitisation etc.

The people here who complain this exists need to complain knives exist too because in the hands of a suitable idiot they can kill people.

Not joking but this also demonstrates that the average USB port is like a public glory hole (no dont google that)

[windsmurf]

not going to defend the guy but, 10 years in prison and a $250,000 fine is beyond insane

US Criminial Justice system is more about harsh punishment, not correction nor rehabilitation, of especially of those without money.