Tutorial: Cracking WEP Using Backtrack 3

Accessing WIFI networks that do not belong to you is ILLEGAL. This article will explan ho w to crack 64bit and 128bit WEP on many WIFI access points and routers using Backtrack, a live linux distribution. Your mileage may very. The basic theory is that we want to connect to an Access Point using WEP Encryption, but we do not know the key. We will attack the wifi router, making it generate packets for our cracking effort, finally cracking the WEP key. I have tested this technique on an IBM Thinkpad x60 and Acer 5672 and the WIFI Chipset in those machines work for sure. Requirements: * Backtrack 3 on CD or USB * Computer with compatible 802.11 wireless card * Wireless Access point or WIFI Router using WEP encryption I will assume that you have downloaded and booted into Backtrack 3. If you haven’t figured that part out, you probably shouldn’t be trying to crack WEP keys. Once Backtrack is loaded, open a shell and do the following: Preparing The WIFI Card First we must enable “Monitor Mode” on the wifi card. If using the Intel® PRO/Wireless 3945ABG chipset issue the following commands: modprobe -r iwl3945 modprobe ipwraw The above commands will enable monitor mode on the wireless chipset in your computer. Next we must stop your WIFI card: iwconfig Take note of your wireless adapter’s interface name. Then stop the adapter by issuing: airmon-ng stop [device] Then: ifconfig down [interface] Now we must change the MAC address of the adapter: macconfig --mac 00:11:22:33:44:66 [device] Its now time to start the card in monitor mode by doing: airmon-ng start [device] airmon-ngstart1.png Attacking The Target It is now time to locate a suitable WEP enabled network to work with: $url[http://thew0rd.com/2008/08/19/tutorial-cracking-wep-using-backtrack-3/,continua...]