MacOS Attack Matrix: User Level Persistence with .zprofile Configuration File (Part — 20)

Login Items is the other method of obtaining User Persistence without Sudo Privileges

Persistence on a MacOS device can be a critical technique for red teamers and penetration testers. It allows attackers to maintain access to a compromised system across reboots and user sessions. One subtle and effective method of achieving persistence is through the use of the .zprofile configuration file. In this article, we'll dive into this technique, showing you how to implement it step-by-step using a Python payload. We'll add some code snippets, analogies, and examples to make the process easy to understand and replicate.

Introduction to .zprofile Persistence

Imagine your MacOS system as a fortress, with multiple gates and guards ensuring that only authorized individuals gain access. Persistence techniques are akin to planting hidden keys that allow unauthorized access whenever needed. The .zprofile file, hidden in the user's home directory, serves as one such key. This file is executed every time a new zsh terminal session is started, making it an excellent candidate for our persistence method.

Step-by-Step Implementation

Step 1: Understanding .zprofile
The .zprofile file is a configuration file for the zsh shell, located in the user's home directory. It runs every time a new zsh terminal session is started. If the file doesn't exist on the system, you can create it. By placing our malicious command in this file, we ensure that it is executed whenever the user opens a terminal.

Step 2: Crafting the Malicious Command
For our proof of concept (PoC), we’ll reuse a Python payload. The goal is to run this payload silently in the background every time the terminal session starts. Here’s the command we’ll use:

bash -c "nohup /Users/USERNAME/Music/evilc2.py > /dev/null 2>&1 &"

Let’s break down this command:

• bash -c starts a new bash instance to run the following command.
• nohup allows the command to run even after the terminal is closed.
• /Users/USERNAME/Music/evilc2.py is the path to our malicious Python script.
• > /dev/null 2>&1 & redirects all output to /dev/null and runs the command in the background.

Step 3: Creating or Modifying the .zprofile File
To create or modify the .zprofile file, follow these steps:
a) Open the terminal.
b) Navigate to the user’s home directory:

cd ~

c) Open the .zprofile file in a text editor. If the file doesn't exist, this command will create it:

nano .zprofile

d) Add the malicious command to the file:

echo 'bash -c "nohup /Users/USERNAME/Music/evilc2.py > /dev/null 2>&1 &"' >> .zprofile

e) Save and close the file (in nano, use Ctrl+O to save and Ctrl+X to exit).

Step 4: Verifying the Persistence
To ensure that the persistence mechanism works, open a new terminal session. The evilc2.py script should run silently in the background without any visual indication to the user.

Practical Example: The Invisible Sentinel

Consider the .zprofile technique as planting an invisible sentinel in the system. This sentinel (our Python script) wakes up and operates in the shadows every time the user opens a terminal session. The user remains blissfully unaware of its presence, as it leaves no trace in the terminal output.

Conclusion

Persistence techniques like the one demonstrated using the .zprofile file highlight the importance of understanding and securing every aspect of a system. By exploiting a seemingly innocuous configuration file, attackers can maintain a foothold on a compromised machine with minimal detection risk.

In our next installment, we’ll explore another innovative MacOS persistence technique that leverages system services for even more stealthy and resilient access. Stay tuned for more insights into the world of MacOS red teaming!

Final Words

By leveraging the .zprofile file, you can effectively maintain persistence on a MacOS device. This technique is a powerful addition to any red teamer's toolkit, providing a reliable way to execute malicious payloads without alerting the user. Keep experimenting, stay vigilant, and always explore new methods to stay ahead in the game of cybersecurity.

Thank you for tuning in and following my MacOS Attack Matrix Series for 20 articles straight! Your dedication and enthusiasm have been incredible, and I appreciate every comment, share, and bit of feedback you’ve provided along the way. It’s been a journey exploring the depths of MacOS security, persistence techniques, and red teaming strategies with you. I hope these insights have empowered you with the knowledge and skills to better understand and defend against advanced threats. Stay with me as we continue to delve into the fascinating world of cybersecurity!