Aircrack-ng is a set of programs designed to detect wireless networks, intercept traffic transmitted over wireless networks, audit WEP and WPA/WPA2-PSK encryption keys (strength test).
Official site: www.aircrack-ng.org
Installs in Ubuntu like this:
sudo apt-get install aircrack-ng
We look at the name of the wireless network interface (it is usually called wlan0):
We scan existing Wi-Fi networks and look at their encryption type, channel, etc.
sudo iwlist scanning
We look at the running network services:
sudo airmon-ng check
sudo stop network-manager
sudo stop avahi-daemon
sudo killall wpa_supplicant
Launch a monitor named mon0:
sudo airmon-ng start wlan0
For convenience, we open a new terminal (so that we can return to the previous one with the list of networks at any time) and intercept all packets into a file (by default it is created in the user’s directory):
sudo airodump-ng --channel N -w wep -i --bssid MAC mon0
Where N is the number of the wifi channel, MAC is the MAC address of the access point.
We select the key from the file:
sudo aircrack-ng -a 1 -0 wep-01.ivs
We start the network-manager network service back so that we can connect to the wireless network:
sudo start network-manager
We connect to the wireless point and enter the security key already known to us.