huntrule

Possible In-Memory Execution Via Reflection.Assembly (via ps_script)

This rule detects use of "Reflection.Assembly" load functions to dynamically load assemblies in memory

SigmamediumWindowsv1
sigma
title: Possible In-Memory Execution Via Reflection.Assembly (via ps_script)
id: 76b093b3-718d-513f-8cd4-8d3408f33eca
status: stable
description: This rule detects use of "Reflection.Assembly" load functions to dynamically load assemblies in memory
references:
    - https://attack.mitre.org/techniques/T1620/
    - https://speakerdeck.com/heirhabarov/hunting-for-powershell-abuse?slide=50
author: Huntrule Team
date: 2026-01-05
tags:
    - attack.stealth
    - attack.t1620
logsource:
    product: windows
    category: ps_script
    definition: Script Block Logging must be enable
detection:
    selection:
        ScriptBlockText|contains: '[Reflection.Assembly]::load'
    condition: selection
falsepositives:
    - Unknown
level: medium

Known false positives

  • Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.