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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."
...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!
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
Probably any reasonably advanced ham operator could pull this off for nothing more than his/her labor and the parts in the junk drawer.
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]
and an amplifier that will broaden the range of the attack to some 120 meters
I got caught.
"This is illegal, you know."
Marriott got fined over half a million dollars for jamming guests' Wi-Fi.
A simple RC circuit, with an appropriate oscillator and power transister will give you a nice sawtooth pattern. The jamming capability all comes down to the power pushed out and the antenna used.
Can also be done with a $15 microwave oven from the nearest Goodwill.
I can do all kinds of bad things with existing technology.
No one jams wireless networks because there's hardly any point aside from "LOLguys watch this".
Are you using unlicensed Wifi spectrum for anything mission critical, such that jamming would be anything more than a slight inconvenience?
More fool you.
Sorry,
You don't need a PhD, knowledge of WiFi, networking protocols or the OSI model.
Any skilled ham could build a circuit to disrupt a targeted portion of the radio spectrum, and probably with ALOT more power than a USB dongle could provide.
...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.
Someone just realized Microwave Ovens can be used to jam wifi.
They wont even allow cell-jammers in prisons where contraband cellphones are everywhere.
MY WIFI IS DOWN, ALL IS LOST, ALL IS LOS........, oh wait, [rummage, rummage, rummage, Ethernet cable found, *click*, *click*] never mind, fixed it.
if this is what passes by as a phd thesis, my dog could hold at least 3. it seriously took a phd student to figure out that wifi is easy to jam. just go to an apartment block where everyone has wifi....your throughoutput drops to nil, add to it a couple of microwaves and a few cordless phones + baby monitors and say goodbye to your wireless communications. seriously standards for phds are really low
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...
About 20 minutes into the presentation, the guy demoes it (works!), and then says that
he is not releasing the code because it could cause trouble.
Duh!
On the flip side, anyone who does do this with said $15 dongle can consequently be located by a resourceful and pissed-off individual using an even cheaper dongle, who can then decide on the proper payba...er...action to take.
I would pay good money to jam all wifi for all devices except mine. Would be great in crowded areas.
Dealextreme used to sell a wifi/cell phone/bluetooth blocker for something like $10.. I have a friend that bought one.. I just went looking though, and it looks like they don't cell them anymore.. Maybe they're trying to seem to be more of a legitimate company or something..
Just send multicast packets over Wi-Fi and every Wi-Fi network in range will suddenly become unusable. I accidentally did that using VLC as a streaming server! It took a few occurrences at different times to finally click on the coincidence.
I still have no idea why that happens. I have a blurry memory that says that the AP drops to "b" mode for multicast, but no reason was given.
"Everybody's naked underneath" -- The Doctor
Prisons should consult with this guy. There is an epidemic of prison visitors in the US sneaking in cell phones inside condoms jammed up the visitors' rectums.
They could run USB cables above the cells and put the jammer at the end of each cable.
You can just turn your microwave oven. It'll do a pretty good job of interfering with WiFI frequency (which is in the microwave band)
Any guest worker system is indistinguishable from indentured servitude.
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."
None of the fun lab equipment is used. Well, maybe there is some brute force. But he's basically flashed the dongle to inject packets into the WLAN and take over via priority. This suppressed the other devices from transmitting so it's a little more elegant than jamming. If the attacker was in WLAN proximity, did not use an amplifier, then it would be hard to detect without packet inspection.
Now we're talking.
I see what you did there.
Wir sind geboren, um frei zu sein - Rio Reiser
For $15, approximately, (certainly for less than the cost of the Dongle, the RaspPi, and the amplifier) you can get something like a Model T spark coil (aka ignition coil, trembler coil, etc) and a battery and generate enough RF noise to swamp anything in the vicinity.
For extra fun, google pocket tesla coil or portable tesla coil.
Gee, and I thought someone discovered that a cheap WiFi-frequency transmitter + a high-gain antenna + constantly transmitting + malicious intent + aiming it at the target = denial-of-service attack 10 or 15 years ago.
My mistake. Please give this guy a Nobel Prize for his clearly groundbreaking research.
Narrator: Thinking quickly, Dave constructs a homemade megaphone using only a squirrel, some string and a megaphone.
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
How about just cutting the power line..
There is nothing intelligent about these sort of simple disruptive attacks, they are nothing more than a form of temporary vandalism. I could probably to a hell of a lot more damage with the guts of an appliance found in most kitchens, but would it prove I am smart? No.
SOMEONE DISCOVERED HOW TO JAM A RADIO SIGNAL BY EMITTING A HIGHER POWER SIGNAL ON THE SAME FREQUENCY, THE SKY IS FALLING, THE SKY IS FALLING, ELVIS SHOT JFK!!!!!
The frontpage of Slashdot is looking more like the news feed on Facebook every day. People posting stupid shit without the competence to understand the basic concepts involved.
"We hope these results aid in the creation of better countermeasures, and motivate
people to only use the more secure (AES)-CCMP."
https://lirias.kuleuven.be/bitstream/123456789/473761/1/acsac2014.pdf
i bet i could do it with a lamp somebody threw away because the cord sparks like crazy where it attaches to the plug.
Star Trek transporters are just 3d printers.
I think I saw this on an episode of Burn Notice...
Wash your keyboard, its kinda gross.