This is a multiple part series for someone new to wireless hacking, with pictures and videos.
Introduction To Kali and WiFi Pen Testing
How to Install Kali Linux
Kali Linux and Reaver
Getting a Handshake and a Data Capture, WPA Dictionary Attack
Using Aircrack and a Dictionary to Crack a WPA Data Capture
Cracking a WPA Capture with the GPU using HashCat
Next Creating a Dictionary / Wordlist with Crunch Part 8
Note: If you are using a updated version of Kali and aicrack-ng mon0 interface has been changed to wlan0mon. Read here for more info.
Kali Linux and Reaver
The Commands we will be using.
airmon-ng start wlan0
wash -i mon0 -C
reaver -I mon0 -b (The BSSID) â€“vv (The -vv is two V not a W)
Reaver is one of the best tools to come along in a long time. Before WPA was implemented and WEP ruled wireless encryption any network could be cracked easily. But when WPA became the standard it became much harder to do and using the dictionary attack method was the only real option. Then came Reaver.
Reaver works by a flaw found in routers called WPS or Wi-fi Protected Setup. WPS makes it easy for wireless devices to find and connect to a router. The problem with WPS is, it has a flaw in it that lets someone go around the encryption.
If a router has WPS enabled then cracking the encryption is no longer necessary. WPS uses pin numbers that are not encrypted. Reaver starts by running through the pin numbers until it is found once it is found it will display the password. If a router has WPS enabled it can usually be cracked in two – ten hours.
“Wi-Fi Protected Setup, or WPS. It is a feature that exists on many routers, intended to provide an easy setup process, and it is tied to a PIN that is hard-coded into the device. Reaver exploits a flaw in these PINs and the result is that, with enough time, it can reveal your WPA or WPA2 password. Reaver does not attempt to take on the WPA encryption itself, but goes around it using WPS and then displaying the password.” (PCM)
As with other attacks there are some problems with this such as signal strength, a strong signal is almost a must. Also some routers can crash if too many pins get thrown at it quickly much like a denial of service attack can crash a PC.
Reaver has many options or switches it can use to deal with these problems. The example I am using below is a basic one. There are many more commands to use with Reaver, you can see them all by typing “reaver /?”.
Setting up the Pen Testing environment
Setup a router with WPA or WPA2 for encryption and give it a password. Enable WPS if it is not already and connect to it wirelessly with a separate device (laptop, smartphone) simulating a real environment.
The first thing we need to do is enable the wireless USB adapter.
Run the command “airmon-ng” to see if Kali recognizes your wireless USB adapter. It should show “Wlan0” along with the chipset, if it doesn’t then some troubleshooting will have to be done until it does.
Finding a WPS enabled router is the next step this used to be hard to do until the “wash” command came along. Before the “wash” command every router would have to be found and then tested to see if WPS was enabled. The “wash” command will list only WPS enabled routers.
The Wash command has been notorious for having problems and not working correctly. Basically the wash command goes out and tells you if a router has WPS enabled, so you dont waste your time running Reaver. I believe I have found a fix that has been working for me on both Backtrack 5 and Kali Linux.
I made a short video on using the Wash command if you are having problems.
If nothing comes up then no WPS enabled router is within reach. Run the following command to see all access point within your reach. “airodump-ng mon0”. Only do this if the wash command finds nothing.
Now we can get to using Reaver. Be sure the terminal window running the “wash” command is not actively using the wireless USB adapter by pressing CTRL+C inside of it. You can copy and paste the BSSID.
Reaver will now run and start a brute force attack against the Pin number of the router. It will run until it finds the wireless password usually 2-10 hours.