hunting-for-anomalous-powershell-execution

Hunt for malicious PowerShell activity by analyzing Script Block Logging (Event 4104), Module Logging (Event 4103), and process creation events. The analyst parses Windows Event Log EVTX files to detect obfuscated commands, AMSI bypass attempts, encoded payloads, credential dumping keywords, and suspicious download cradles. Activates for requests involving PowerShell threat hunting, script block analysis, encoded command detection, or AMSI bypass identification.

16 stars

Best use case

hunting-for-anomalous-powershell-execution is best used when you need a repeatable AI agent workflow instead of a one-off prompt.

Hunt for malicious PowerShell activity by analyzing Script Block Logging (Event 4104), Module Logging (Event 4103), and process creation events. The analyst parses Windows Event Log EVTX files to detect obfuscated commands, AMSI bypass attempts, encoded payloads, credential dumping keywords, and suspicious download cradles. Activates for requests involving PowerShell threat hunting, script block analysis, encoded command detection, or AMSI bypass identification.

Teams using hunting-for-anomalous-powershell-execution should expect a more consistent output, faster repeated execution, less prompt rewriting.

When to use this skill

  • You want a reusable workflow that can be run more than once with consistent structure.

When not to use this skill

  • You only need a quick one-off answer and do not need a reusable workflow.
  • You cannot install or maintain the underlying files, dependencies, or repository context.

Installation

Claude Code / Cursor / Codex

$curl -o ~/.claude/skills/hunting-for-anomalous-powershell-execution/SKILL.md --create-dirs "https://raw.githubusercontent.com/plurigrid/asi/main/plugins/asi/skills/hunting-for-anomalous-powershell-execution/SKILL.md"

Manual Installation

  1. Download SKILL.md from GitHub
  2. Place it in .claude/skills/hunting-for-anomalous-powershell-execution/SKILL.md inside your project
  3. Restart your AI agent — it will auto-discover the skill

How hunting-for-anomalous-powershell-execution Compares

Feature / Agenthunting-for-anomalous-powershell-executionStandard Approach
Platform SupportNot specifiedLimited / Varies
Context Awareness High Baseline
Installation ComplexityUnknownN/A

Frequently Asked Questions

What does this skill do?

Hunt for malicious PowerShell activity by analyzing Script Block Logging (Event 4104), Module Logging (Event 4103), and process creation events. The analyst parses Windows Event Log EVTX files to detect obfuscated commands, AMSI bypass attempts, encoded payloads, credential dumping keywords, and suspicious download cradles. Activates for requests involving PowerShell threat hunting, script block analysis, encoded command detection, or AMSI bypass identification.

Where can I find the source code?

You can find the source code on GitHub using the link provided at the top of the page.

SKILL.md Source

# Hunting for Anomalous PowerShell Execution

## Overview

PowerShell Script Block Logging (Event ID 4104) records the full deobfuscated script text
executed on a Windows endpoint, making it the primary data source for hunting malicious
PowerShell. Combined with Module Logging (4103) and process creation events, analysts can
detect encoded commands, AMSI bypass patterns, download cradles, credential theft tools,
and fileless attack techniques even when the attacker uses obfuscation layers.


## When to Use

- When investigating security incidents that require hunting for anomalous powershell execution
- When building detection rules or threat hunting queries for this domain
- When SOC analysts need structured procedures for this analysis type
- When validating security monitoring coverage for related attack techniques

## Prerequisites

- Windows Event Log exports (.evtx) from Microsoft-Windows-PowerShell/Operational
- Python 3.8+ with python-evtx and lxml libraries
- Script Block Logging enabled via Group Policy
- Understanding of common PowerShell attack techniques

## Steps

1. Parse EVTX files extracting Event 4104 script block text and metadata
2. Reassemble multi-part script blocks using ScriptBlock ID correlation
3. Scan script text for AMSI bypass indicators and obfuscation patterns
4. Detect encoded command execution and base64 payloads
5. Identify download cradles, credential dumping, and lateral movement commands
6. Score and prioritize findings by threat severity

## Expected Output

```json
{
  "total_events": 1247,
  "suspicious_events": 23,
  "amsi_bypass_attempts": 2,
  "encoded_commands": 8,
  "download_cradles": 5,
  "credential_access": 3
}
```

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