Null Byte How-Tos

How To: Buy Bitcoin Anonymously — A Guide to Investing in Cryptocurrency While Maintaining Privacy

Just like cash, bitcoin is used for everything from regular day-to-day business to criminal activities. However, unlike physical cash, the blockchain is permanent and immutable, which means anyone from a teen to the US government can follow every single transaction you make without you even knowing about it. However, there are ways to add layers of anonymity to your bitcoin transactions.

How To: Use Cerberus to Take Control of Anyone's Android Phone

If you need to hack an Android device, try a remote administration tool. Known more familiarly as a RAT, there are open-source RATs that are barebones and exorbitantly priced RATs that are more polished. There are also low-cost and polished RATs that aren't intended to be RATs at all, such as Cerberus, an anti-theft solution available right on Google Play.

How To: Exploit Shellshock on a Web Server Using Metasploit

One of the most critical bugs to come out in the last five years was Shellshock, a vulnerability which allows attackers to execute arbitrary code via the Unix Bash shell remotely. This vulnerability has been around for a while now, but due to the ubiquity of Unix machines connected to the web, Shellshock is still a very real threat, especially for unpatched systems.

How To: Use MDK3 for Advanced Wi-Fi Jamming

You may have heard of a signal jammer before, which usually refers to a device that blasts out a strong enough radio signal to drown out the reception of nearby devices like cell phones. Purpose-built jammer hardware is outright illegal in many countries. Still, Wi-Fi is vulnerable to several different jamming attacks that can be done with Kali Linux and a wireless network adapter.

How To: Securely Sync Files Between Two Machines Using Syncthing

Transferring hundreds of screenshots, webcam recordings, keystroke logs, and audio recordings between your VPS and a local Kali machine can be tricky. Services like Dropbox don't always have the best privacy policies and suffer data breaches just like any other website. To mitigate these risks, we'll use a secure, open source, and decentralized alternative.

How To: Beginner's Guide to OWASP Juice Shop, Your Practice Hacking Grounds for the 10 Most Common Web App Vulnerabilities

Web application vulnerabilities are one of the most crucial points of consideration in any penetration test or security evaluation. While some security areas require a home network or computer for testing, creating a test website to learn web app security requires a slightly different approach. For a safe environment to learn about web app hacking, the OWASP Juice Shop can help.

How To: Use Command Injection to Pop a Reverse Shell on a Web Server

Command injection is a technique used by hackers to execute system commands on a server, usually via a web application or some kind of GUI. This can happen when an application provides some sort of functionality to the user involving the use of system commands. When the input is not properly sanitized, commands not originally intended to be run are allowed to be executed.

Locking Down Linux: Using Ubuntu as Your Primary OS, Part 3 (Application Hardening & Sandboxing)

Once you've installed Ubuntu with security in mind and reduced the possibility of network attacks on your system, you can start thinking about security on an application level. If a malicious file is opened on your system, will an attacker be able to access every file on the computer? The chances are much slimmer if you put the proper defenses in place.

Locking Down Linux: Using Ubuntu as Your Primary OS, Part 2 (Network Attack Defense)

After installing Ubuntu as your primary OS, you should have protected against USB Rubber Ducky payloads, defended against hard drive forensics, and reduced the overall attack surface against physical strikes. When defending against network-based attacks, you'll want to minimize hardware disclosures, prevent packet sniffers, harden firewall rules, and much more.

How To: Perform Directory Traversal & Extract Sensitive Information

With all the web applications out on the internet today, and especially the ones built and configured by novices, it's easy to find vulnerabilities. Some are more perilous than others, but the consequences of even the slightest breach can be tremendous in the hands of a skilled hacker. Directory traversal is a relatively simple attack but can be used to expose sensitive information on a server.

How To: Use Beginner Python to Build a Brute-Force Tool for SHA-1 Hashes

Developers creating login systems know better than to store passwords in plain text, usually storing hashes of a password to prevent storing the credentials in a way a hacker could steal. Due to the way hashes work, not all are created equal. Some are more vulnerable than others, and a little Python could be used to brute-force any weak hashes to get the passwords they were created from.

How To: The Beginner's Guide to Defending Against Wi-Fi Hacking

Hacking Wi-Fi is a lot easier than most people think, but the ways of doing so are clustered around a few common techniques most hackers use. With a few simple actions, the average user can go a long way toward defending against the five most common methods of Wi-Fi hacking, which include password cracking, social engineering, WPS attacks, remote access, and rogue access points.

How to Hack Wi-Fi: Disabling Security Cameras on Any Wireless Network with Aireplay-Ng

Electronic warfare tactics work by jamming, disrupting, or disabling the technology a target uses to perform a critical function, and IoT devices are especially vulnerable to attacks. Wireless security cameras like the Nest Cam are frequently used to secure critical locations, but a hacker can surgically disable a webcam or other Wi-Fi connected device without disturbing the rest of the network.

Hacking macOS: How to Remotely Eavesdrop in Real Time Using Anyone's MacBook Microphone

Google, Amazon, and Facebook are always listening. But what's worse? Hackers are listening, too. Windows PCs are particularly vulnerable, but with a few simple commands, a remote attacker can even take over the microphone on someone's Mac computer, streaming audio and listening to private conversations in real time without the victim's knowledge, abusing an overlooked security consideration.

How To: Use Maltego to Fingerprint an Entire Network Using Only a Domain Name

Hackers rely on good data to be able to pull off an attack, and reconnaissance is the stage of the hack in which they must learn as much as they can to devise a plan of action. Technical details are a critical component of this picture, and with OSINT tools like Maltego, a single domain name is everything you need to fingerprint the tech details of an organization from IP address to AS number.

SQL Injection 101: How to Avoid Detection & Bypass Defenses

It is often said that the best hackers remain unknown, and the greatest attacks are left undiscovered, but it's hard for an up-and-coming penetration tester or white hat to learn anything unless one of those factors is actually known or discovered. But the end goal here in our SQL injection lessons is to make that statement as true as possible for us when performing our hacks.

How To: Install & Lock Down Kali Linux for Safe Desktop Use

Kali Linux is established as the go-to operating system for penetration testing, but in its default configuration, it's less than ideal for regular desktop use. While in many scenarios, a live boot or virtual environment can resolve these issues, in some situations, a full installation is better. A few simple changes can be made to a Kali Linux desktop to make it safer to use in this environment.