In today's digital world, where wireless technologies permeate every aspect of our lives, the security of transmitted data is becoming critical. Many users still take their home network for granted, without considering how easily an attacker can intercept traffic or gain unauthorized access to devices. That's why tools for penetration testing, such as Termux, are becoming not just a toy for enthusiasts, but a serious diagnostic arsenal in the hands of system administrators.
Using an Android mobile device with a Linux terminal emulator installed allows for in-depth analysis of the radio frequency spectrum and encryption protocols directly in the field. However, it's important to set boundaries: any actions aimed at disrupting another person's network or stealing data without the owner's written permission are illegal. Termux In this context, it is considered solely as a means of testing one's own infrastructure for vulnerabilities and understanding the principles of information security.
In this article, we'll take a detailed look at the technical aspects of working with wireless interfaces, the principles of handshakes, and the security methods you need to use to ensure your network remains impenetrable. We won't discuss hacking methods for free internet access, as this is unethical and illegal. Our goal is educational: to demonstrate how security works so you can properly configure your equipment.
Preparing the working environment and setting up Termux
The first step to getting started with network analysis tools is properly installing and configuring the operating environment. Termux is not just an emulator, but a fully-fledged Linux-like environment that requires careful attention to access rights and repositories. The default installation from the Google Play Market is often outdated, so for up-to-date packages, we recommend using the version from F-Droid or the project's official GitHub repository.
After installing the application, you need to update the packages and install basic utilities, which are essential for further operation. In the terminal, this appears as a sequence of commands that download the necessary binaries and libraries. It's important to understand that standard Android doesn't provide applications with direct access to the Wi-Fi module in monitor mode, which is a key limitation for conducting a full audit.
pkg update && pkg upgradepkg install git python wget curl proot
pkg install root-repo
To expand functionality, it is often necessary to install additional packages, such as tsu (similar to sudo) and ncurses-utilsThese tools allow you to run scripts with superuser privileges, which is necessary for interacting with network equipment. Without root privileges, analysis capabilities are significantly limited, as most network utilities require low-level access to drivers.
⚠️ Attention: Attempting to root your device using unofficial methods may void your warranty and compromise the Android security system (SafetyNet), making it impossible for banking apps to function.
Particular attention should be paid to your device's compatibility with external Wi-Fi adapters. Built-in smartphone modules rarely support monitor mode and packet injection, which are necessary for professional auditing. Therefore, for serious work, connecting an external USB adapter via an OTG cable is often required. Drivers for this adapter should be built into your device's Android kernel or firmware (e.g., Kali Nethunter).
☑️ Preparing Termux for work
Wireless network operating principles and vulnerabilities
To effectively secure a network, it is necessary to understand how exactly data is exchanged between the client and the access point. Security protocols such as WEP, WPA, WPA2 and new WPA3, use various encryption algorithms and authentication methods. The old WEP standard was completely compromised years ago due to the weakness of the RC4 algorithm, and its use today is tantamount to a lack of security.
Modern networks most often use WPA2-Personal, which relies on a four-way handshake for security. When a device connects to the router, special frames are exchanged containing password hashes, but not the cleartext password itself. Security audit In this case, it consists of trying to intercept this handshake and find a password for it using brute force or a dictionary.
Vulnerabilities often stem not from the encryption protocol itself, but from human error: using weak passwords, not regularly updating router firmware, or not having the WPS function enabled. The WPS (Wi-Fi Protected Setup) protocol, designed to simplify device connections, contains a critical vulnerability in the PIN code, allowing someone to recover the network password in a matter of hours or even minutes.
| Protocol | Encryption algorithm | Security status | Recommendation |
|---|---|---|---|
| WEP | RC4 | Critically vulnerable | Do not use |
| WPA | TKIP | Outdated | Replace with WPA2 |
| WPA2 | AES (CCMP) | Safe (with a complex password) | Recommended |
| WPA3 | SAE | Maximum protection | The optimal choice |
It's important to note that even the strongest encryption protocol is vulnerable to man-in-the-middle attacks if the user ignores browser certificate warnings or connects to open access points. Understanding these mechanisms allows the administrator to build multi-layered defenses, including network segmentation and the use of guest VLANs.
What is deauthentication?
Deauthentication is an attack in which an attacker sends special control frames on behalf of an access point to a client (or vice versa), forcibly breaking the connection. This is a legitimate protocol mechanism that allows a device to switch to another access point with a better signal, but it lacks the cryptographic protection of the WPA2 standard, making it useful for testing clients' resilience to connection interruptions.
Traffic analysis and network monitoring
One of the basic functions available in Termux, even without monitor mode (in a limited form) or with an external adapter, is scanning the surrounding radio space. Utilities like iwlist or specialized scripts allow you to see the list of available networks, their channels, signal level (RSSI) and encryption types. This is the first stage of the audit, allowing us to assess the "noisiness" of the airwaves and the presence of suspicious access points.
With compatible equipment and root privileges, the operator can perform a more in-depth analysis using sniffing tools. Sniffing involves setting the network card to a mode that captures all packets passing through the network, not just those addressed to a specific device. This allows for analyzing packet headers, identifying unencrypted data (e.g., HTTP, Telnet), and studying the behavior of devices on the network.
termux-wifi-connectioninfoor for advanced users with an external adapter:
ifconfig wlan0 down
iwconfig wlan0 mode monitor
ifconfig wlan0 up
airodump-ng wlan0
When monitoring, it's important to pay attention to the number of clients connected to a specific access point and the rate of data exchange. Sudden traffic spikes or devices attempting to connect to hidden SSIDs may indicate unauthorized access attempts or automated scanners. Log analysis helps to identify anomalies in the operation of network equipment.
It's important to remember that active scanning and especially attempts to penetrate other networks may be considered an attack by your provider or security systems (IDS/IPS). Therefore, all experiments should be conducted exclusively in an isolated lab or on your own equipment, disconnected from the global network, unless you are certain of the legality of your actions.
Testing the strength of passwords and handshakes
The central element of home network security is the password. Brute-force attacks on it are the primary focus of audits. After intercepting a handshake between a legitimate client and the router, a file is saved to disk. This file contains hashes that can be decrypted offline using powerful graphics cards and specialized software, such as Hashcat or John the Ripper.
The effectiveness of a brute-force attack depends directly on the password complexity and the dictionary used. If a user uses a password like "12345678" or their date of birth, it can be brute-forced in seconds, even on a regular smartphone. Using complex combinations of symbols, numbers, and upper- and lower-case letters increases the brute-force attack time to astronomical levels, making the attack economically and temporarily unfeasible.
⚠️ Attention: Password cracking puts a heavy load on the device's processor and battery. Extended brute-force sessions can cause the smartphone to overheat and accelerate battery life. Monitor your device's temperature!
In addition to direct dictionary attacks, there are rainbow table methods, which are pre-computed hashes for millions of combinations. However, modern hashing methods (such as PBKDF2 in WPA2) make rainbow tables less efficient than WEP, requiring a huge amount of memory to store the tables.
To improve security, we recommend using passwords at least 12-15 characters long, including special characters. Regularly changing passwords and avoiding using the same passwords on different devices is also an effective protection method. Two-factor authentication, where possible (for example, to access the router's admin panel), adds another layer of protection.
Protection from attacks and security recommendations
Understanding attack methods allows you to formulate clear defense rules. The first and most important step is to avoid using the protocol. WPSThis feature, which allows you to connect by pressing a button or entering a PIN, is a security hole that can be used to access the network even with a complex WPA2 password. WPS must be disabled in your router's settings.
The second important aspect is updating the router's firmware. Manufacturers regularly release patches that fix vulnerabilities in the device's software. Old routers that no longer receive updates from the vendor pose a potential threat and should be replaced with more modern models that support the standard. WPA3.
It's also recommended to hide the SSID (network name) and configure a MAC address filter, although these measures aren't a panacea. A hidden SSID is easily detected by sniffers, and MAC addresses can be spoofed. However, when combined with other measures, this creates an additional barrier to attack. A more effective measure is to create a guest network for visitors, isolated from the main local network where your personal data is stored.
| Protective measure | Efficiency | Difficulty of implementation | Comment |
|---|---|---|---|
| Disabling WPS | High | Low | Necessarily |
| Complex password | Critical | Low | The basis of security |
| Hiding the SSID | Low | Low | Protection from "neighbors" |
| MAC filter | Average | Average | Labor-intensive to maintain |
| Guest network | High | Low | Isolation of guests |
Don't forget about physical security either. Access to the reset button on the router should be restricted, as physical access to the device often allows an attacker to reset the settings and gain complete control. Place routers in locations inaccessible to unauthorized persons.
Legal and ethical aspects of testing
The use of security audit tools such as Termux, Aircrack-ng, or Reaver is regulated by law in most countries. In the Russian Federation, for example, Articles 272, 273, and 274 of the Russian Criminal Code provide for liability for unauthorized access to computer information and the creation and use of malware. Even running a scanner on someone else's network without permission can be considered an attempt at unauthorized access.
An ethical hacker (white hat) always operates within the law and has written consent from the infrastructure owner to conduct tests. All actions must be documented, and the resulting data must be destroyed immediately after the audit is completed. The goal of the work is to identify vulnerabilities for their elimination, not for personal exploitation.
If you discover a neighbor's open or vulnerable network, the appropriate action is not to attempt connection, but to inform the owner of the risks (if possible and safe) or to ignore their infrastructure. Conduct any experiments only on your own equipment, specifically set up for testing (a lab environment).
⚠️ Attention: Cybersecurity legislation is constantly changing. Before undertaking any network analysis activity, be sure to familiarize yourself with the current laws in your jurisdiction. Ignorance of the law is no excuse.
The professional community adheres to a strict code of ethics that prioritizes data confidentiality, integrity, and availability. Violating these principles discredits the entire information security industry and causes real harm to individuals and organizations.
Can you go to jail for using Termux?
Termux itself is a legal tool, like a hammer or a screwdriver. Liability arises not for the possession of the tool, but for the actions performed with it. If you use it to hack into other people's networks, steal data, or disrupt services, you are subject to criminal prosecution.
Frequently Asked Questions (FAQ)
Do I need root to use Wi-Fi in Termux?
Root access may not be required for basic network scanning, but for a full-fledged security audit, including packet sniffing, frame injection, and running in monitor mode, superuser (root) privileges are absolutely necessary. Without them, access to low-level Wi-Fi driver functions is blocked by the Android system.
Does the smartphone's built-in Wi-Fi module work for auditing?
In 95% of cases, built-in smartphone modules don't support monitor mode and packet injection, as driver manufacturers don't enable these features. For serious work, an external USB Wi-Fi adapter with Atheros or Ralink chips that supports these modes and has the appropriate drivers in the Android kernel (for example, via Kali Nethunter) is required.
Is it safe to install Termux from the Play Market?
The Google Play Market version is no longer updated by the developers and may contain outdated components. For the most current and secure version, we recommend using the F-Droid repository or downloading the APK from the official Termux project GitHub repository.
Is it possible to hack WPA3 using Termux?
Currently, the WPA3 protocol is considered cryptographically secure. Dragonblood-type attacks are theoretically possible, but require complex hardware and conditions unavailable through standard Termux on a smartphone. Brute-forcing WPA3 passwords is also extremely difficult thanks to the SAE (Simultaneous Authentication of Equals) mechanism.
Which adapter is best for a beginner?
A good starting point would be adapters based on the Realtek RTL8812AU or Atheros AR9271 chipset, which are well-supported in the Kali Linux and Nethunter communities. They are relatively inexpensive and support 2.4 and 5 GHz frequencies, while supporting the necessary monitoring modes.