The Android mobile platform has long since ceased to be simply a tool for making calls and playing games, having transformed into a powerful pocket computer capable of handling system administration tasks. Terminal emulation environment Termux provides users with access to the package manager pkg and a full-fledged Linux command line, which opens up opportunities for in-depth analysis of network protocols. In the context of information security, this means that a smartphone can become a tool for testing the security of one's own wireless network from unauthorized access.
It's important to immediately clarify the limits of what is permitted: using specialized software to hack into other people's networks without the owner's written permission is illegal and falls under the criminal code's provisions on unauthorized access to computer information. The purpose of this article — purely educational, aimed at demonstrating the vulnerabilities of encryption protocols and teaching methods for protecting personal data. Understanding the mechanics of attacks is essential for building a robust security perimeter.
Auditing wireless networks requires not only installing the appropriate software but also understanding the physical limitations of the hardware. Standard WiFi modules in smartphones often operate in client mode and do not support switching to monitor mode, which is critical for intercepting handshakes. However, a theoretical framework and software emulation methods allow us to understand the operating principles of encryption algorithms. WPA/WPA2.
Technical prerequisites and equipment limitations
Before installing utilities, it's important to understand that the success of the operation directly depends on the hardware. Most smartphones have built-in WiFi chips. Qualcomm or Broadcom have closed drivers that do not allow switching to monitoring mode without reflashing the kernel or using external adapters. Monitor mode Allows the network interface to capture all packets in the air, ignoring addressing, which is the foundation for traffic analysis.
For full functionality, it is often necessary to connect an external USB adapter via the port OTGSuch adapters should be based on chipsets with open drivers, for example, Atheros AR9271 or Ralink RT3070Without support for packet injection and monitor mode at the driver level, most attacks become impossible, and the user will only be able to scan the airwaves, but not actively interact with them.
⚠️ Attention: Attempting to enable monitor mode on an unsupported integrated module may result in unstable WiFi operation, system freezes, or the need to reset network settings to factory defaults. Always check the chipset specifications before experimenting.
Modern Android operating systems strictly isolate processes, so working with network interfaces often requires superuser rights. rootWithout these rights, access to low-level network stack functions will be limited to standard APIs, making it impossible to execute many commands from the set. aircrack-ngHowever, there are workarounds through creating virtual interfaces, although their effectiveness varies depending on the Android version.
Installing and configuring tools in Termux
Getting started with the terminal requires updating repositories and installing basic dependencies. The standard package manager pkg Allows you to quickly deploy the required environment. The first step should always be updating package lists to avoid library version conflicts when installing cryptographic utilities.
pkg update && pkg upgrade
pkg install root-repo
pkg install tsu wget python-wifi-repeater git
The main tool for security audit is the package aircrack-ng, which includes a set of utilities for monitoring, packet capture, and penetration testing. Installation is via the standard repository, but some devices may require compiling from source code to support specific drivers.
- 📦 aircrack-ng — a basic set of tools for assessing the security of WiFi networks, including programs for capturing and injecting packets.
- 📡 reaver — a utility for carrying out brute-force attacks on WPS PIN codes, which is relevant for older routers.
- 🔓 hashcat — an advanced password recovery tool that uses the computing power of the GPU (in case of emulation or external resources).
After installation, you need to check the status of the network interface. Command ip link or ifconfig will show available devices. For most tools to work, the interface must be renamed and set to the appropriate mode, although on mobile devices this often requires the use of wrapper scripts such as Wifi-Kill or Nethunter (if using a custom kernel).
☑️ Checking Termux's readiness for audit
How WPA2 encryption algorithms work
Understanding how exactly traffic is protected is key to understanding the risks. Protocol WPA2-PSK (Pre-Shared Key) uses a four-way handshake to authenticate the client and access point. During this process, temporary encryption keys are generated, but the password itself is never transmitted over the network in cleartext.
Instead of transmitting a password, devices exchange hashes calculated from the password and a random number (nonce). An attacker in monitor mode can capture packets of this handshake. If the intercepted data contains the full four-way handshake, it can be saved to a file for later offline analysis.
| Parameter | Description | Role in security |
|---|---|---|
| SSID | Wireless network name | Used as "salt" when generating the PMK key. |
| Nonce | A random number generated once | Ensures the uniqueness of each communication session |
| MIC | Message Integrity Code | Confirms that the packet has not been modified in transit |
| PMK | Paired master key | A derivative of the password, not transmitted over the air |
The weak point is the human factor: users often choose simple passwords. Algorithm PBKDF2The key generation algorithm is deliberately slow to make brute-force attacks more difficult, but short character combinations can be brute-forced in reasonable time on modern hardware.
Why is WPA3 better?
The WPA3 protocol implements SAE (Simultaneous Authentication of Equals) protection, which makes it impossible to intercept a handshake for subsequent offline brute-force attacks. Even if an attacker intercepts packets, they won't be able to launch a dictionary attack without real-time interaction with the access point.
Methodology for Intercepting and Analyzing Handshakes
The process of obtaining data for analysis begins with switching the interface to monitor mode. In the Termux environment, this is often done using the command airmon-ng start wlan0, Where wlan0 — the name of your interface. This creates a virtual interface, usually called wlan0mon, which is capable of listening to the entire broadcast.
The next step is to search for the target network. The utility airodump-ng Scans channels and displays a list of available access points with their MAC addresses (BSSIDs), channels, and signal strengths. It's important to select a network with active clients, as this is when the handshake occurs.
airodump-ng -c [CHANNEL] --bssid [ROUTER_MAC] -w /sdcard/capture wlan0mon
If there are no active clients on the network, they can be forcibly disconnected to trigger automatic reconnection. This is done using a deauthentication attack, which sends control frames on behalf of the router, denying the client connection. This attack is aggressive and easily detected by security systems (WIDS).
- 🎯 Target designation: Knowing the exact BSSID and channel is critical to avoid polluting the capture file with unnecessary data.
- ⏳ Expectation: Sometimes you have to wait a few minutes until the client itself decides to reconnect to the network.
- 💾 Preservation: file with extension
.capcontains raw data which is then converted into a format.hccapxfor hashcatter.
Password recovery and dictionary attacks
After successfully capturing the handshake, the cryptanalysis phase begins. Directly "computing" the password from the hash is mathematically impossible due to the properties of one-way hashing functions. The only way is trial and error. This is accomplished using dictionaries—text files containing millions of frequently used passwords.
Tool aircrack-ng Allows you to run the brute-force process directly in Termux, using the smartphone's processor. The command accepts a capture file and a path to the dictionary. Brute-force speed depends on the CPU power, but on mobile devices it is relatively slow compared to desktop GPUs.
aircrack-ng -w /sdcard/wordlists/rockyou.txt /sdcard/capture-01.cap
If the password is in a dictionary, it will be displayed on the screen. However, if the password is unique and complex (a set of random characters), then a brute-force attack could take years. That's why password length and complexity are the main factors of protection. Using the dictionary rockyou.txt Allows you to find passwords that users have created based on popular cultural patterns.
Protecting your home network from unauthorized access
Knowing how hacking tools work makes it much easier to build an effective defense. The first and most important step is to stop using the protocol. WPS (Wi-Fi Protected Setup). This feature, designed to simplify device connections, contains a fundamental design flaw that allows the PIN code to be recovered within a few hours.
It's essential to update your router firmware regularly. Manufacturers patch security holes that could lead to remote attacks or administrator privileges. Outdated firmware is an open door for attackers, even if you have a strong WiFi password.
⚠️ Attention: Don't use default passwords for your router's administrative panel (e.g., admin/admin). An attacker who gains access to your network can easily gain complete control of your equipment if this information isn't changed.
Enabling MAC address filtering creates an additional barrier, although it's not a panacea, as MAC addresses are easily spoofed. However, when combined with hiding the SSID (network name) and using a protocol WPA3 (If the hardware supports it), the security level increases significantly. WPA3 eliminates the handshake vulnerability, rendering intercepted packets useless to an attacker.
Frequently Asked Questions (FAQ)
Is it possible to hack WiFi using Termux without root access?
Without root access, capabilities are severely limited. You can scan for networks, but you can't switch the built-in WiFi module to monitor mode to capture handshakes using standard Android APIs. Rooting or using external adapters that support special modes via OTG is required.
Is Termux safe to use for network auditing?
The app itself is safe and virus-free. However, running attack scripts may be considered malicious activity by your ISP or network owner. Furthermore, using unverified scripts from the internet can lead to your own device being compromised.
How long does it take to crack a password?
The time depends on the password's complexity and the device's performance. A simple 6-8 character password can be cracked in minutes or hours. A 12+ character password with mixed case and special characters would take centuries to crack on a mobile processor, making the attack impractical.
Does aircrack-ng require internet access in Termux?
The packet capture and password cracking process itself doesn't require an internet connection; all calculations are performed locally. However, an internet connection is required for installing packages and downloading brute-force dictionaries.