Potential DLL File Download Via PowerShell Invoke-WebRequest — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems), Hieu Tran. Source status: test; severity: medium. Source dates: 2023-03-13 / 2025-07-18.

{
  "product": "windows",
  "category": "process_creation"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: ea9bdcd2c9ef362ebab5afa71b122974fde44cc3c070b5d51a7884a605faf250

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential DLL File Download Via PowerShell Invoke-WebRequest
id: 0f0450f3-8b47-441e-a31b-15a91dc243e2
status: test
description: Detects potential DLL files being downloaded using the PowerShell Invoke-WebRequest or Invoke-RestMethod cmdlets.
references:
    - https://www.zscaler.com/blogs/security-research/onenote-growing-threat-malware-distribution
author: Florian Roth (Nextron Systems), Hieu Tran
date: 2023-03-13
modified: 2025-07-18
tags:
    - attack.command-and-control
    - attack.execution
    - attack.t1059.001
    - attack.t1105
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        CommandLine|contains:
            - 'Invoke-RestMethod '
            - 'Invoke-WebRequest '
            - 'IRM '
            - 'IWR '
        CommandLine|contains|all:
            - 'http'
            - 'OutFile'
            - '.dll'
    condition: selection
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.zscaler.com/blogs/security-research/onenote-growing-threat-malware-distribution