Jamming Wi-Fi With a $15 Dongle

An anonymous reader writes with this report about just how easy it is to disrupt if not entirely kill modern consumer-grade networks -- not just Wi-Fi, but Bluetooth and Zigbee networks, too. Crucial to determining the likelihood of any given kind of attack, though, is how much it would cost the attacker to attempt. The bad news for network owners and users is that it doesn't cost much at all: "According to Mathy Vanhoef, a PhD student at KU Leuven (Belgium), it can easily be done by using a Wi-Fi $15 dongle bought off Amazon, a Raspberry Pi board, and an amplifier that will broaden the range of the attack to some 120 meters."

Comments

With a $15 dongle?

[aardvarkjoe]

...it can easily be done by using a Wi-Fi $15 dongle bought off Amazon, a Raspberry Pi board, and an amplifier that will broaden the range of the attack to some 120 meters.

In other news, I can build myself a car with a $3 roll of duct tape bought off Amazon, as long as I happen to have all the other pieces sitting in my garage. Astounding!

Re:With a $15 dongle?

[GuB-42]

It is not really the point here but I hate it when I see "build X with $5" when you actually need at least $100 worth of junk that, somehow, every people must have. And that's not counting the tools.

Re:With a $15 dongle?

[sobachatina]

I know!

And they never even account for the costs of the person's education or years of experience.
They don't list the cost of the the facility where a project like this can be built without being rained on.
Or the health care over the years to ensure that one's hands and mind function adequately for the task.
They don't even account for the cost of the calories of food required for thought and motor control.

This project would actually cost >$1,000,000

Seriously though, if you are committed to a hobby, there are many projects that will be much cheaper for you than for a person who has not yet entered that hobby. It is normal to only list consumable components in the list of prices. Tools, for example, are a sunk cost and not consumable so they are not listed. I often see this frustration from visitors to hacking and hobbyist sites. People who are upset that getting into a hobby requires an upfront investment in time and money that then makes everything else cheaper.

That said- I agree that the rPi and amp should have been listed. Even if it is likely that a person would have an rPi around- it is still consumed by the project.

Re:With a $15 dongle?

[Hylandr]

> Kidding aside, the statement isn't as stupid as you make it out to be. You just need to be a little more open minded for the evil possibilities.

No kidding here at all, I want this for my car or motorcycle. I want 100 foot bubble of no people talking or texting when I am on the highway ! ( +/- 10 Ft )

Re:With a $15 dongle?

[sexconker]

You'd have a bubble where people were fiddling with their phones because it just crapped out on them.

Re:With a $15 dongle?

[Hylandr]

Uhg,

Fair enough. I drop my bid for a Cell-free bubble in favor of an EMP burst from 200 miles up. Lets just go back to castles and fiefdoms.

Re: With a $15 dongle?

[ememisya]

Misleading title indeed. I think what is worthy of attention here is that wireless "security" cameras aren't very useful unless they actively shift their frequency and amplitude based on the environment, and send out an alert along the lines of, "We are under attack" through cable means. Hey, there's an idea, too bad frequencies to shift inbetween are severly limited by regulation but should thwart a noob with a powerful transmitter.

Re:With a $15 dongle?

[bws111]

Sorry. A guy in Florida was fined $48000 by the FCC for operating a cell phone jammer in his car to prevent others near him from using their phones.

PhD

[darkain]

Wait, it took a PhD student to figure out that broadcasting malicious signals disrupts signals on the similar wavelengths? And OMGs it effects BlueTooth, too!? Totally didn't know that two personal usage wireless communication specs would both be using unlicensed spectrum, WHO WOULDA THOUGHT!?

I can do it for quite a bit less. Just put a small piece of plastic into the door switch of a microwave so it thinks it is closed, but leave it open. Now turn it on. You can cook yourself while killing Wifi all throughout the house! [DISCLAIMER, DON'T ACTUALLY DO THIS]

Re:PhD

[Gliscameria]

That's how you know it's working.

As Kravindish would say:

[tepples]

"This is illegal, you know."

Marriott got fined over half a million dollars for jamming guests' Wi-Fi.

Wifi.

[ledow]

Are you using unlicensed Wifi spectrum for anything mission critical, such that jamming would be anything more than a slight inconvenience?

More fool you.

In other news...

[SecurityGuy]

...did you know that you can render a car inoperable with a device as simple and cheap as a nail? That you can destroy many electronics simply by getting them wet? That you can harm a person simply by swinging a fist into them? Etc, etc, etc.

Yes, we know this. For many things, it's not possible to make them unbreakable, therefore we enact societal consequences for breaking them like jail, fines, etc. It's been that was for, well, all of recorded history.

Re:FCC will go ballistic over this

[gstoddart]

First off .. it's Belgium, so not so much with the FCC.

But, really, if you assume a malicious actor, why the hell would they care?

If it's cheap and easy to do it, people probably will. It's not like the FCC (or any other agency) has the ability to prevent the attacks just by saying you're not allowed to do it.

Re:Isn't that illegal?

[silas_moeckel]

You're still intentionally interfering so you're never going to be legal.

Serious consequence? Please

[cdrudge]

With the above mentioned networks being crucial to the functioning of many IoT devices and systems - home security systems, car locks, baby monitors, and so on - it should be obvious that the fact that these attacks can be performed so easily and cheaply may lead to serious consequences.

If your IoT device, home security system, car locks, baby monitors, and so on have serious consequences if their crucial wireless network is unavailable, you have a serious design flaw in your system. At worst, it should result in the particular thing not communicating and you resort to a back up method, such as say a door lock, a key, or going and checking on your kid in person...

It's not just brute force jamming

[Zeorge]

Brute force is easy. From the article, he flashed the $15 dongle to take priority over the WLAN and prevents others from TX'ing. He's not just raising the noise floor. This makes it a little harder to detect. I guess if you had a spectrum analyzer or were looking at the RSSI you would see an abnormally strong signal. If you were paying attention to your WLAN, you'd see a device that -potentially- wasn't part of the WLAN broadcasting and supressing everyone else. I'm at work so I can't read more of it, but, I'd like to know if these were open networks with no type of WEP or WPA2 or MAC filtering versus ones that had that utilized. Be interesting if a rogue device could inject packets into the WLAN without seeing any data but just taking priority.

"During his recent presentation at BruCON, Vanhoef explained that by modifying the dongle's firmware he was able to force the target networks to always give priority to the device's transmissions. If the device is made to transmit continuously, it means that all other devices won't be able to, making the channel effectively unusable.

His attempts at selective jamming (blocking specific packets) have been less successful, and he concluded that 100% reliable selective jamming is not possible."

Well. . . .

[nehumanuscrede]

I suppose walking about with a dongle sized piece of hardware is a bit more subtle than toting around a microwave attached to a backpack. :D