5 Ways to Backdoor a Windows System

ice-wzl
4 min readMay 29, 2023

Introduction:

As a red team operator, it is crucial to continually explore advanced techniques to effectively simulate real-world threats during authorized penetration tests. Backdooring Windows systems provides a powerful avenue for unauthorized access and control. In this reference manual, we will explore five advanced ways to backdoor a Windows system, equipping red team operators with the knowledge and techniques necessary to conduct sophisticated and stealthy operations. Each technique will be accompanied by detailed command descriptions or code snippets, enabling red team operators to execute these methods effectively.

Technique: DLL Hijacking

DLL hijacking involves replacing a legitimate Dynamic Link Library (DLL) with a malicious one to execute unauthorized code when a vulnerable application loads the hijacked DLL. Here’s an example of how to exploit DLL hijacking:

# Identify vulnerable applications and their associated DLLs
dir /s /b C:\Path\To\Target\Application.exe
# Replace the legitimate DLL with the malicious one
copy C:\Path\To\Malicious.dll C:\Path\To\Target\Application.dll

By replacing the legitimate DLL (e.g., Application.dll) with the malicious DLL (e.g., Malicious.dll), the backdoor is injected when the vulnerable application is executed.

Technique: Registry Modification

Manipulating the Windows Registry can grant unauthorized access to systems. Here’s an example of modifying the Registry to backdoor a Windows system:

# Create a new Registry key
reg add HKLM\Software\Microsoft\Windows\CurrentVersion\Run /v Backdoor /t REG_SZ /d "C:\Path\To\Backdoor.exe"

By creating a new Registry key (Backdoor) under HKLM\Software\Microsoft\Windows\CurrentVersion\Run and pointing it to the location of the backdoor executable (C:\Path\To\Backdoor.exe), the backdoor is automatically executed when the system starts up.

Technique: PowerShell Script Injection

Leveraging the versatility of PowerShell, injecting malicious scripts provides an effective means of compromising Windows systems. This technique allows red team operators to execute…

--

--

ice-wzl

Reverse Engineer, Red Teamer, CTF fan & creator