Questions about how to access someone else's network often arise out of curiosity or a desire to test one's own security. However, it's important to set boundaries right away: Kali Linux β This is a professional tool for ethical hacking and security auditing, not a toy for internet hijacking. Using these methods on networks you don't own is illegal and punishable by law.
The purpose of this article is to explain the workings of wireless protocols to administrators and enthusiasts and demonstrate how security professionals find vulnerabilities. Understanding the mechanics of attacks is the only way to build a reliable defense. We will cover the theoretical aspects, necessary tools, and the steps involved in conducting a legal attack. Penetration Testing (penetration testing).
Before proceeding with any practical work, it's important to understand the responsibility involved. Any actions must be performed exclusively in laboratory conditions or on one's own equipment with the written permission of the infrastructure owner. The legislation of most countries equates unauthorized access to computer information with a criminal offense.
Environment preparation and equipment requirements
For effective wireless network analysis, a laptop's standard built-in Wi-Fi module is often insufficient. Most built-in cards only operate in client mode and do not support the necessary features for intercepting traffic. You'll need an external USB adapter that supports this mode. Monitor Mode and package injections.
Popular chipsets that work reliably with the Kali toolkit include: Atheros AR9271, Ralink RT3070 And Realtek RTL8812AUWhen choosing a device, carefully study the manufacturer's specifications, as even the same adapter model may come with different chips depending on the revision.
β οΈ Warning: Using monitor mode may temporarily disrupt your primary access point. We recommend testing on a separate router, not connected to your primary network, to avoid accidental connection interruptions.
After connecting the adapter, you need to make sure that the operating system correctly recognizes the device. In the terminal, use the command ip link or iwconfig to check the interface status. If the card is displayed but doesn't support the required functions, you may need to install additional drivers or reflash the firmware.
βοΈ Audit readiness check
Setting the wireless interface to monitoring mode
A key preparation step is switching the network interface from the standard management mode (Managed Mode) to Monitor Mode. In its normal state, the network card filters packets addressed only to it, ignoring all other traffic. Monitor Mode Allows the card to capture all radio signals within range, whether they are intended for your device or not.
The most commonly used utility to manage interfaces in Kali Linux is aircrack-ngBefore starting processes, you must stop system services that may block access to the adapter, for example, NetworkManager or wpa_supplicantThis is a critical step, without which further manipulations will be impossible.
The switching process can be automated using a utility airmon-ng. Team airmon-ng start wlan0 will create a new virtual interface (usually with a suffix mon0), which is ready to listen to the broadcast.
sudo airmon-ng check kill
sudo airmon-ng start wlan0
Once monitoring mode is activated, the airwaves are flooded with data. You'll see thousands of frames per second, including service packets, connection requests, and user data. This stream of information is analyzed to identify weaknesses in the network configuration.
Analysis of the surrounding ether and search for targets
Once the interface is set up, the exploration phase begins. The tool airodump-ng Allows you to visualize all available wireless networks within range. The screen displays a list of access points (APs) with their SSIDs, MAC addresses (BSSIDs), channels used, and signal strength.
Particular attention should be paid to the column ENC (encryption) and AUTH (authentication). Modern networks use WPA2 or WPA3 protocols, while the outdated WEP is becoming less common but still poses a threat in older devices. It's also important to monitor the speaker. #Data, which shows the volume of data transferred.
To narrow your search, you can filter the utility's output by specifying a specific channel and BSSID of the target network. This will reduce processor load and allow you to focus on the target of interest. Packet captures are saved to a file for later in-depth analysis.
sudo airodump-ng --channel 6 --bssid 00:11:22:33:44:55 --write target_audit wlan0monDuring scanning, you may notice that some networks don't broadcast their names (SSID Hidden). However, hiding the name isn't a security measure, as the SSID is broadcast in clear frames when any authorized client connects. Auditing tools easily identify such "hidden" networks.
Attack methods and password strength testing
There are several attack vectors for wireless networks, each exploiting protocol vulnerabilities. The most common method for WPA2 is a 4-Way Handshake attack. When a client connects to an access point, a key exchange occurs, and if an attacker intercepts this, they can obtain the password hash.
To force a client to reconnect, a deauthentication method is used. Using the utility aireplay-ng Special packets are sent that terminate the connection between the legitimate device and the router. The device automatically attempts to reconnect, generating a new handshake, which is captured by the sniffer.
β οΈ Warning: Sending deauthentication packets en masse may be interpreted by your ISP or security systems as a DDoS attack. Use this method only on an isolated testbed with a single client device.
The resulting handshake file (.cap or .hccapx) does not contain the cleartext password itself. A brute-force or dictionary attack is used to recover it. The utility hashcat or aircrack-ng It goes through millions of combinations, comparing hashes with the captured data.
The effectiveness of this method directly depends on the complexity of the password. Simple combinations like "12345678" or "password" are recovered in seconds. However, long passwords containing special characters can take years to crack, confirming the importance of using complex passcodes.
Comparison of security protocol vulnerabilities
Understanding the differences between security standards helps you choose the right security strategy. The table below compares the main protocols and their resistance to modern auditing methods.
| Protocol | Encryption type | Vulnerability | Recommendation |
|---|---|---|---|
| WEP | RC4 | Critical (hack in minutes) | Do not use |
| WPA (TKIP) | TKIP | High (MIC key) | Replace with AES |
| WPA2 (AES) | CCMP/AES | Medium (depending on password) | Minimum standard |
| WPA3 | SAE | Low (brute force protection) | Recommended |
As can be seen from the table, the protocol WEP is completely dead and offers no security. Even WPA with TKIP encryption is considered insecure due to the possibility of packet injection. The gold standard currently remains the WPA2/WPA3 combination with encryption. AES.
However, even WPA3 isn't a panacea. Attacks like Dragonblood exist that theoretically allow for a weakening of the connection's security. Therefore, security is a process, not an end state, requiring constant firmware updates.
What is a PMKID attack?
The PMKID attack allows one to obtain a password hash without the need for connected clients. The router itself provides the required hash in response to a request, making it possible to hack networks that don't currently have active users.
Practical steps to protect your home network
Knowing how hacking tools work makes it much easier to build an effective defense. The first and most important rule is to avoid using factory passwords. Default administrator credentials and Wi-Fi keys are often published in open databases and are publicly known.
Use long passwords (more than 12 characters) containing mixed-case letters, numbers, and special characters. This exponentially increases the time required for brute-force attacks, making the attack cost- and time-consuming.
β οΈ Please note: Router interfaces and security settings may vary depending on the model and firmware version. Always consult the manufacturer's official documentation before changing critical network settings.
Additionally, it is recommended to disable the function WPS (Wi-Fi Protected Setup). This protocol, designed to simplify device connections, has fundamental vulnerabilities that allow PIN codes to be recovered in a matter of hours, even with a complex Wi-Fi password.
Update your router's firmware regularly. Manufacturers often patch security holes discovered by researchers. Older versions of the software may contain backdoors that allow you to bypass Wi-Fi security altogether, gaining complete control of the device.
Is it legal to use Kali Linux to test your Wi-Fi?
Yes, it's completely legal. You have every right to test the security of your own equipment. Legal issues will only arise if you attempt to access other people's networks or interfere with your neighbors' devices.
Is it possible to hack Wi-Fi from an Android phone?
Theoretically, it's possible if the phone is rooted and the chipset supports monitor mode. However, the performance of mobile processors is significantly lower than that of PCs, and the range of available tools is limited. A full-fledged OS, such as Kali Linux, is still required for a serious audit.
Will the protection work if I hide the network name (SSID)?
No, hiding the SSID is not a security measure. It simply hides the network name from the regular list of available connections on your neighbors' phones. Specialized scanners can easily detect such networks, and their traffic remains open to analysis unless encryption is used.
Which adapter is best for a beginner?
For starters, adapters based on Atheros AR9271 chips are the best choice. They offer excellent out-of-the-box compatibility with Kali Linux, don't require complex driver installation, and offer stable monitor mode, allowing you to focus on learning the principles rather than fiddling with the hardware.