Decoding Malicious PowerShell Activity - Advanced Obfuscation Techniques

A Fan-Favorite Investigation

Decoding Malicious PowerShell Activity - A Case Study has been a widely shared and well-received deep dive into PowerShell obfuscation. This blog provided a foundational look into how attackers manipulate PowerShell scripts to evade detection, making it a great starting point for those new to the topic.

The Next Chapter: Deep Dive into PowerShell Obfuscation

In this second installment, we take a closer look at advanced PowerShell obfuscation techniques. Attackers have evolved far beyond basic string manipulation and compression. They now employ:

• Weaponizing Operators: -join, -split, -f
• Whitespace Tricks: Leveraging invisible characters to bypass detection
• Special Characters: Drowning scripts in encoded and deceptive symbols
• Deceptive Execution: Obfuscating iex (Invoke-Expression) in creative ways
• Script Block Logging Evasion: Manipulating PowerShell’s logging features
• Multi-Layered Obfuscation: Heavily obfuscated VBS payloads leading to PowerShell execution

⚡ Hands-On Practice Scripts

By popular demand, this repository contains a collection of practice scripts to help you analyze and deobfuscate malicious PowerShell code. These scripts simulate real-world attack patterns, giving you a chance to hone your threat-hunting and incident response skills.