Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/26zl/cybersec-toolkit/deobfuscating-powershell-obfuscated-malwarenpx skills add 26zl/cybersec-toolkit --skill deobfuscating-powershell-obfuscated-malwaregit clone --depth 1 https://github.com/26zl/cybersec-toolkitWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/26zl/cybersec-toolkit/deobfuscating-powershell-obfuscated-malware)<a href="https://agentmods.dev/skills/26zl/cybersec-toolkit/deobfuscating-powershell-obfuscated-malware"><img src="https://agentmods.dev/badge/skills/26zl/cybersec-toolkit/deobfuscating-powershell-obfuscated-malware.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00048 | $0.03358 |
| Opus 5 | $0.00024 | $0.01679 |
| Sonnet 5 | $0.00010 | $0.00672 |
| Haiku 4.5 | $0.00005 | $0.00336 |
Grade A, and why
deobfuscating-powershell-obfuscated-malware scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
result = subprocess.run( This is a copy
100% identical to deobfuscating-powershell-obfuscated-malware — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 389 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Deobfuscating PowerShell Obfuscated Malware
Overview
PowerShell is heavily abused by malware authors due to its deep Windows integration and powerful scripting capabilities. Obfuscation techniques include string concatenation, Base64 encoding, character substitution, Invoke-Expression layering, SecureString abuse, environment variable manipulation, and tick-mark insertion. Modern malware uses multiple obfuscation layers requiring iterative deobfuscation. Tools like PSDecode, PowerDecode, and PowerPeeler automate much of this process, while manual AST (Abstract Syntax Tree) analysis handles custom obfuscation. PowerPeeler achieves a 95% deobfuscation correctness rate using instruction-level dynamic analysis of expression-related AST nodes.
When to Use
- When performing authorized security testing that involves deobfuscating powershell obfuscated malware
- When analyzing malware samples or attack artifacts in a controlled environment
- When conducting red team exercises or penetration testing engagements
- When building detection capabilities based on offensive technique understanding
Prerequisites
- Python 3.9+ with
base64,re,subprocessmodules - PowerShell 5.1+ or PowerShell 7+ (for AST access)
- PSDecode (
Install-Module PSDecode) - PowerDecode (https://github.com/Malandrone/PowerDecode)
- Isolated VM or sandbox for safe script execution
- CyberChef for manual encoding transformations
- Understanding of PowerShell AST and Invoke-Expression patterns
Key Concepts
Common Obfuscation Techniques
PowerShell malware employs layered obfuscation to evade static detection. String concatenation splits commands across variables ($a='In'+'voke'). Base64 encoding wraps entire scripts in -EncodedCommand parameters. Character code arrays use [char] casting ([char[]](73,69,88)|%{$r+=$_}). Environment variable abuse reads substrings from $env: paths. Tick-mark insertion adds backticks between characters that PowerShell ignores (Invoke-Expression`). SecureString conversion encrypts strings using ConvertTo-SecureString with embedded keys.
What ships with it
7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 389 lines · 48 tokens per session scan A 68584b7ed6f6
deobfuscating-powershell-obfuscated-malware is a skill published in the GitHub repository 26zl/cybersec-toolkit (48 stars, last pushed 3d ago), licensed MIT. It adds 48 tokens to every session and 3,358 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). It is 100% identical to deobfuscating-powershell-obfuscated-malware, differing in 0 lines, and is treated as a copy.
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