Once, when I was a teenager, I was staying in a hotel. I was all like, “Oh, I’d like to have Wi-Fi now please because I feel weirdly uncomfortable not having it at all times.” There were all these Wi-Fi networks around, but I didn’t know the password to any of them. Which made me think… what if I could… use it anyway? This prompted a lot of research and devastated that particular family holiday.
This article is the 100 per cent code-free explanation of one way someone might hack your home Wi-Fi. By the end it’s okay to feel afraid, insecure, or even cripplingly alone. It’s okay. We’ve all been there.
The first thing I’d do is take out my laptop and run airodump-ng, a suite of software tools for exactly the job of hacking Wi-Fi. It would show me the names of Wi-Fi networks and also their “BSSID”, which is a bit like an ID for Wi-Fi networks. It’s actually exactly like that.
Once I know the BSSID of your Wi-Fi, it’s time to try and get your password hash. A password hash is like a scrambled version of the password. You can’t unscramble it. Kinda like how you can’t unscramble scrambled eggs back into the white and the yolk. Stop trying, it’s embarrassing. Okay, so let’s get the hash and then worry about getting the password out of it.
We’re going to find it by watching the secret handshake.
You heard me. I can’t believe that this is a real thing, but there actually is a secret handshake that happens when you connect to a Wi-Fi network.
You might be wondering why there’s a secret handshake happening every time you connect to Wi-Fi. And that’s fair enough, I’m glad you asked.
Let’s say you’re a legitimate businessperson just connecting to their home Wi-Fi. No funny business. You know the password. But you need to prove to the Wi-Fi network that you know the password. But everyone else can hear you.
It’s kinda like if you came up to me at a party and you said “I know your Facebook password”. It gets real tense. I nervously glance up at you and choke trying to chuckle. I want to know if you really do know my Facebook password, but I also don’t want you to just say “Your Facebook password is cooldude99” because everyone else at the party is listening.
So, the secret handshake lets you and the Wi-Fi router both prove you know the password without saying it. Here’s how it works:
Did you spot the trick? What can an eavesdropper do here? The trick here is that if you’re an eavesdropper, you get to see the following things:
Well what if I just encrypt the text “memes” with “cooldad1964” as the key, and it happens to encrypt to “b8%&G”?
Then I know that the password was “cooldad1964”. And if “memes” encrypts to something else, then I know my guess was wrong.
So what we’re going to do here is just guess the password. The trick is that we’re going to be able
to guess passwords way faster than if we were just typing them into the “Enter the password for this Wi-Fi network” box.
So, get out your pen and paper and blow the dust off that compass and straightedge because it’s time to do some encryption.
Just kidding, we’re not going to use pen and paper you big bozo. We’re going to use a graphics card.
Graphics cards are the part inside a computer that lets the computer be able to play 3D games such as Fallout 4 and Viva Piñata: Party Animals. They also happen to be really fast at encrypting stuff.
So we’re going to get a big list of millions of passwords, and try them all to try and guess the Wi-Fi password.
For one reason or another, hackers have made available big lists of real passwords. By “real”, I mean “someone used this password on a site and that site got hacked so now everyone knows their password”. Sites that got hacked recently and had passwords exposed include LinkedIn, Adobe, and Myspace.
I’m going to guess that your Wi-Fi password is probably in one of the heaps big lists of passwords I have. But to find out which one it is, we’re going to have to encrypt “memes” (in this example) with every single password in the list as the key, and see if any of them match what we saw the Wi-Fi password encrypt to (“b8%&G”).
Hashcat is software that can take a password list and a hash (“b8%&G”) and try to “unhash” it by comparing it to all the passwords in the list. To give you an estimate of how long this takes, my computer can check 10 million passwords in about 10 minutes.
And that’s it. Hashcat will spit out the password, and I can just type it in the Wi-Fi “Enter the password” box. The main part is furiously guessing millions of passwords until we find the right one.
The reason this method of hacking works is because people pick easy-to-guess passwords. English word with the first letter maybe capitalised then one or two numbers? That pattern covers a LOT of people’s passwords and a computer can just quickly check all of them.
If you’re an average internet user, your password for everything is the same, and it’s your pet’s name followed by your house number. What I’m saying is that on average, most Wi-Fi passwords don’t stand a chance against these password lists.
And of course, if all that doesn’t work, I could just send you a fake email that says “Suspicious activity detected in your Netgear router – Log In now to review” and get your password that way.
Art includes elements by factor[e] design initiative and Viktor Vorobyev, used with permission through The Noun Project