Insert at least a 4GB USB stick first because from my experience I get an error saying I have run out of space after about 4 hours of building the capture file. We are going to use the stick to save to our capture to.
Now we go into the flash drive via the command line interface so our capture file gets dumped there otherwise you risk running into a disk full error after a few hours as I have before. Then run the “airmon-ng” command in the terminal to show the WiFi interface. Then we stop the WiFi interface, then bring it down so we can change the MAC Address. Once we do that we bring the interface back online.
Now we start scanning for available WiFi access points within range of the WiFi interface.
Once we find a target we copy the MAC Address as the example below indicates.
We then paste the MAC Address into the command string we want to run.
After entering the MAC Address add “wlan0” interface at the end of the command string.
You will see the following come up. We need to wait for the “#Data” number to hit at least 10000 so we have enough data for the crack to search through for a correct key. Then hit CTRL + C to cancel the “Data” capture. Then we make sure you have the .cap file and initiate the crack.
After a few seconds you should have a key.
{Update: March 28th 2013} I have just posted “WPA2 Cracking with BackTrack 5 R3” Enjoy…