Null Byte How-Tos

How to Hack Wi-Fi: Cracking WPA2 Passwords Using the New PMKID Hashcat Attack

Cracking the password for WPA2 networks has been roughly the same for many years, but a newer attack requires less interaction and info than previous techniques and has the added advantage of being able to target access points with no one connected. The latest attack against the PMKID uses Hashcat to crack WPA passwords and allows hackers to find networks with weak passwords more easily.

How To: Detect & Classify Wi-Fi Jamming Packets with the NodeMCU

The most common Wi-Fi jamming attacks leverage deauthentication and disassociation packets to attack networks. This allows a low-cost ESP8266-based device programmed in Arduino to detect and classify Wi-Fi denial-of-service attacks by lighting a different color LED for each type of packet. The pattern of these colors can also allow us to fingerprint the tool being used to attack the network.

How To: Use an ESP8266 Beacon Spammer to Track Smartphone Users

Smartphones and laptops are constantly sending Wi-Fi radio signals, and many of these signals can be used to track us. In this guide, we'll program a cheap IoT device in Arduino to create hundreds of fake networks with common names; This will cause nearby devices to reveal their real trackable MAC address, and it can even let an attacker take over the phone's data connection with no warning.

How To: Exploit Java Remote Method Invocation to Get Root

In the world of technology, there's often a trade-off between convenience and security. The Java Remote Method Invocation is a system where that trade-off is all too real. The ability for a program written in Java to communicate with another program remotely can greatly extend the usability of an app, but it can also open up critical vulnerabilities that allow it to be compromised by an attacker.

How To: Use Metasploit's WMAP Module to Scan Web Applications for Common Vulnerabilities

Having an efficient workflow is an integral part of any craft, but it's especially important when it comes to probing apps for vulnerabilities. While Metasploit is considered the de facto standard when it comes to exploitation, it also contains modules for other activities, such as scanning. Case in point, WMAP, a web application scanner available for use from within the Metasploit framework.

How To: Get Started Writing Your Own NSE Scripts for Nmap

The road to becoming a skilled white hat is paved with many milestones, one of those being learning how to perform a simple Nmap scan. A little further down that road lies more advanced scanning, along with utilizing a powerful feature of Nmap called the Nmap Scripting Engine. Even further down the road is learning how to modify and write scripts for NSE, which is what we'll be doing today.

How To: The Easy Way to Use PGP for Encrypting Emails on Windows, Mac & Linux

In order to increase the security and harden the integrity of an email account and its content, you'll want to use PGP on your Windows, macOS, or Linux computer. This is usually the first thing security analysts do to protect communications with encryption, and everyone else should consider it too, especially since there's an easy way to incorporate PGP that anyone can follow.

How To: Exploit Remote File Inclusion to Get a Shell

A simple security flaw can allow an attacker to gain a strong foothold with little effort on their part. When a web application permits remotely hosted files to be loaded without any validation, a whole can of worms is opened up, with consequences ranging from simple website defacement to full-on code execution. For this reason, RFI can be a promising path to obtaining a shell.

Hacking macOS: How to Perform Situational Awareness Attacks, Part 1 (Using System Profiler & ARP)

The first few minutes after gaining access to a MacBook are critical — but where do we begin? Using tools built into macOS, we can develop an in-depth understanding of running background processes, detect antivirus software, locate sensitive files, and fingerprint other devices on the network. All of this can be done without installing additional software or modifying any files.

How To: Discover Open Ports Using Metasploit's Built-in Port Scanner

One of the first steps in reconnaissance is determining the open ports on a system. Nmap is widely considered the undisputed king of port scanning, but certain situations call for different tools. Metasploit makes it easy to conduct port scanning from directly inside the framework, and we'll show you three types of port scans: TCP, SYN, and XMAS.

How To: Abuse Session Management with OWASP ZAP

It's always a good idea to know how an attack works at the very basic level. Manual techniques for exploitation often find holes that even the most sophisticated tool cannot. Sometimes, though, using one of these tools can make things so much easier, especially if one has a solid foundation of how it works. One such tool can help us perform a cross-site request forgery with minimal difficulty.

How To: Manipulate User Credentials with a CSRF Attack

Web 2.0 technology has provided a convenient way to post videos online, keep up with old friends on social media, and even bank from the comfort of your web browser. But when applications are poorly designed or incorrectly configured, certain flaws can be exploited. One such flaw, known as CSRF, allows an attacker to use a legitimate user's session to execute unauthorized requests to the server.

How To: Crack Shadow Hashes After Getting Root on a Linux System

After gaining access to a root account, the next order of business is using that power to do something more significant. If the user passwords on the system can be obtained and cracked, an attacker can use them to pivot to other machines if the login is the same across systems. There are two tried-and-true password cracking tools that can accomplish this: John the Ripper and Hashcat.

How To: Program a $6 NodeMCU to Detect Wi-Fi Jamming Attacks in the Arduino IDE

Hackers and makers are often grouped under the same label. While hackers draw on computer science skills to write programs and find bugs, makers use electrical engineering to create hardware prototypes from microprocessor boards like the Arduino. We'll exercise both sets of skills to program a $6 NodeMCU to display the status of a Wi-Fi link via an LED, allowing us to monitor for jamming attacks.

Mac for Hackers: How to Set Up a MacOS System for Wi-Fi Packet Capturing

MacOS isn't known as an ideal operating system for hacking without customization, but it includes native tools that allow easy control of the Wi-Fi radio for packet sniffing. Changing channels, scanning for access points, and even capturing packets all can be done from the command line. We'll use aliasing to set some simple commands for easy native packet capture on a macOS system.

How To: Perform Local Privilege Escalation Using a Linux Kernel Exploit

Getting root is considered the Holy Grail in the world of Linux exploitation. Much like SYSTEM on Windows, the root account provides full administrative access to the operating system. Sometimes even a successful exploit will only give a low-level shell; In that case, a technique called privilege escalation can be used to gain access to more powerful accounts and completely own the system.

Hacking macOS: How to Use One Tclsh Command to Bypass Antivirus Protections

Using Netcat to backdoor a macOS device has its short-comings. If the compromised Mac goes to sleep, the Netcat background process will occasionally fail to terminate correctly; This leaves Netcat running infinitely in the background and the attacker with no new way into the device. As an alternative, we'll use the lesser-known Tcl shell which can handle abrupt backdoor disconnections.