Web ApplicationAugust 25, 2023How to Protect Your Computer from Pastejacking?

As technology advances, so do the methods used by hackers to exploit vulnerabilities and gain control of our devices. One such way is pastejacking, a technique malicious websites employ to take control of your computer’s clipboard and replace its contents with malicious data. This can lead to various cyber threats, including phishing attacks, malware infections, and the theft of sensitive information. This comprehensive guide will explore pastejacking, why it is dangerous, and, most importantly, how to protect your computer from this insidious threat. 

Understanding Pastejacking: What it is and How it Works? 

Pastejacking is a technique malicious websites use to gain control of the clipboard on your computer and replace its contents with malicious data without your knowledge. When you copy and paste text or code from a website, the malicious website runs a command that returns the copied content with something else. This can include links to malicious websites, harmful code, or commands compromising your system’s security. 

Pastejacking is initiated when a user copies content from a website. The malicious web page tracks specific actions, such as keyboard shortcuts (Ctrl+C) or right-click to copy. After a short period, usually around 800 milliseconds, the website replaces the content on your clipboard with the malicious data. This means that when you go to paste the content, you unwittingly paste the malicious data instead. 

It is important to note that pastejacking can occur when copying and pasting into a command prompt or terminal and other applications like text editors or word processors. This means seemingly harmless actions like copying and pasting into Notepad can still pose a risk. 

Dangers of Pastejacking: Why You Should be Concerned 

Pastejacking poses significant risks to your computer and personal information. By replacing the content on your clipboard with malicious data, hackers can trick you into executing harmful commands or visiting malicious websites. Here are some of the key dangers associated with paste jacking: 

a. Phishing Attacks 

One of the most common uses of pastejacking is redirecting unsuspecting users to phishing websites. Phishing websites mimic legitimate websites, such as online banking portals or email login pages, to steal your login credentials or personal information. By replacing a copied link with a malicious phishing URL, hackers can trick you into visiting their fake website and unknowingly provide them with sensitive data. 

b. Malware Infections 

Pastejacking can also be used to deliver malware to your computer. By replacing harmless code or commands with malicious ones, hackers can trick you into executing the malware on your system. This can lead to various malware infections, including ransomware, spyware, or keyloggers, which can compromise your data and privacy. 

c. Data Theft 

Another danger of pastejacking is the theft of sensitive data. By replacing copied text or code with commands that extract or transmit your personal information, hackers can access your credentials, financial details, or other sensitive data. This can lead to identity theft, financial loss, or other serious consequences. 

Protecting Yourself from Pastejacking: Best Practices and Tips 

Now that we understand the risks of pastejacking, we must proactively protect ourselves and our devices. Here are some best practices and tips to help you safeguard against paste-jacking attacks: 

a. Type Instead of Copying and Pasting 

One of the simplest ways to avoid pastejacking is to manually type commands or text instead of copying and pasting them from websites. By ordering the commands yourself, you can ensure you are not inadvertently pasting malicious code or commands from the clipboard. While this may take more time and effort, it significantly reduces the risk of falling victim to pastejacking attacks. 

b. Use a Text Editor as a Buffer 

If you must copy and paste commands or text from websites, using a text editor as a buffer is recommended. Instead of pasting directly into a command prompt or terminal, paste the content into a text editor such as Notepad. This will allow you to review the pasted content and ensure it matches your intended copy. Adding this extra step lets you catch any potential pastejacking attempts and protect your system from malicious commands. 

c. Enable Clipboard Notifications 

Some operating systems allow you to enable clipboard notifications, which will alert you whenever something is copied to your clipboard. By enabling this feature, you can keep track of any suspicious activity and be alerted if your clipboard contents are unexpectedly changed. This can serve as an early warning system for potential pastejacking attempts and allow you to take action before any harm is done. 

d. Use a Password Manager with Autofill 

Using a password manager with autofill capabilities can help protect you from pastejacking attacks when entering login credentials. Password managers like LastPass or 1Password automatically fill in your login information without copying and pasting. This eliminates the risk of falling victim to pastejacking when entering sensitive information into login forms. 

e. Be Mindful of Image Copy and Paste 

While pastejacking primarily targets text and code, it’s worth noting that images can also be used to deliver malicious content. Exercise caution when copying and pasting images, especially from unknown or untrusted sources. Instead of directly pasting photos, it is safer to right-click on the image and select “Save As” to download it. This ensures you are not inadvertently pasting any hidden commands or malicious code within the image. 

f. Keep Your Software Updated 

Regularly updating your operating system, web browser, and security software is crucial for protecting against various cyber threats, including pastejacking attacks. Updates often include security patches and bug fixes that address known vulnerabilities, making it harder for hackers to exploit your system. Make sure to enable automatic updates whenever possible to ensure you are always running your software’s latest, most secure versions. 

g. Educate Yourself and Stay Informed 

Staying informed about the latest cybersecurity threats and best practices is essential for protecting yourself from pastejacking and other attacks. Take the time to educate yourself about common attack techniques, such as pastejacking, and learn how to recognize and avoid potential risks. Stay updated with security news, follow reputable cyber security blogs, and consider attending cybersecurity webinars or workshops to expand your knowledge and stay one step ahead of hackers. 

Practical Application: Pastejacking in Kali Linux 

To provide a practical understanding of how pastejacking works, we will explore an example using Kali Linux, a popular penetration testing and ethical hacking distribution. Please note that this example is for educational purposes only and should not be used for malicious activities. 

a. Installing the PasteJacker Tool 

The PasteJacker tool is an automated script that can simulate pastejacking attacks. To install the PasteJacker tool in Kali Linux, follow these steps: 

1) Clone the PasteJacker repository from GitHub by running the following command in the terminal: 

git clone https://github.com/D4Vinci/PasteJacker  

2) Install the required Python packages by running the following command: 

sudo python3 -m pip install ./PasteJacker  

b. Running PasteJacker 

Once the PasteJacker tool is installed, you can run it in the terminal to simulate pastejacking attacks. Here is an overview of how to use the tool: 

1) Run the PasteJacker tool by running the following command: 

sudo pastejacker  

2) The tool will display a menu with different options for creating pastejacking payloads. Choose the desired option based on the type of attack you want to simulate. 

3) Follow the prompts and provide the necessary information to generate the pastejacking payload. The tool will generate the payload code or command for you to use. 

Paste jacking starts listening on local host port 8082. Open browser, navigate to localhost:8082 and we can see the normal looking test “hack the planet”. If we copy the text and paste it in a mousepad test editor, we can see our actual payload. 

Note: Please note that using the PasteJacker or similar tools for malicious purposes is illegal and unethical. Always use such tools responsibly and with the proper authorization. 


Pastejacking is a dangerous technique used by hackers to exploit the clipboard functionality of your computer and replace its contents with malicious data. Understanding the risks associated with pastejacking and implementing best practices to protect yourself can significantly reduce the chances of falling victim to such attacks. Remember to type commands instead of copying and pasting, use a text editor as a buffer, enable clipboard notifications, and stay informed about the latest cybersecurity threats. By following these guidelines and remaining vigilant, you can keep your computer and personal information safe from the dangers of pastejacking. 

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Prince Varghese

by Prince Varghese

Associate Security Consultant | Redfox Security