Windows PowerShell execution with download-related command line patterns

Alerts when PowerShell is started with command-line fragments indicative of downloading remote content.

FreeReviewedSigma · Medium · v1

Product: windows
Category: process_creation
Author: Florian Roth (Nextron Systems), oscd.community, Jonhnathan Ribeiro (SigmaHQ), DRL 1.1
Published: 2019-01-16
Updated: 2026-07-30

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags process creation events where PowerShell (powershell.exe, powershell_ise.exe, or pwsh.exe) is launched and its command line contains specific download-related constructs. Attackers often use PowerShell to fetch remote content or stage payloads, and the presence of these string fragments indicates automated download behavior. The detection relies on Windows process creation telemetry, matching the process image and command line substrings.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange

Suspicious Script Interpreter Spawned by Explorer via ClickFix Run Dialog (via process_creation)

Suspicious PowerShell Download Cradle via ClickFix Fake CAPTCHA (via process_creation)

Suspicious PowerShell EncodedCommand Spawned From Command Shell via Process Creation

Suspicious Script Download via Curl and PowerShell by Dohdoor

Malicious Mass Hyper-V Virtual Machine Shutdown via PowerShell by Kraken Ransomware

Suspicious PowerShell WebClient DownloadFile of Archive Payload (UAT-7237)

Suspicious SharePoint Worker Process Spawning Command Interpreter via ToolShell

Malicious Emmenhtal JavaScript Loader Spawning Encoded PowerShell

Suspicious Python Interpreter Launching Encoded PowerShell via subprocess

Windows PowerShell execution with download-related command line patterns

Pivot detection · T1059.001 · 9 related

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

windows-powershell-execution-with-download-related-command-line-patterns-3b6ab547

title: Windows PowerShell execution with download-related command line patterns
id: 9e07d713-d286-483c-a53c-79aaa277c6a3
related:
  - id: e6c54d94-498c-4562-a37c-b469d8e9a275
    type: derived
  - id: 8f70ac5f-1f6f-4f8e-b454-db19561216c5
    type: obsolete
  - id: 3b6ab547-8ec2-4991-b9d2-2b06702a48d7
    type: derived
status: test
description: This rule flags process creation events where PowerShell (powershell.exe, powershell_ise.exe, or pwsh.exe) is launched and its command line contains specific download-related constructs. Attackers often use PowerShell to fetch remote content or stage payloads, and the presence of these string fragments indicates automated download behavior. The detection relies on Windows process creation telemetry, matching the process image and command line substrings.
references:
  - https://blog.redteam.pl/2020/06/black-kingdom-ransomware.html
  - https://lab52.io/blog/winter-vivern-all-summer/
  - https://hatching.io/blog/powershell-analysis/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_powershell_download_patterns.yml
author: Florian Roth (Nextron Systems), oscd.community, Jonhnathan Ribeiro, Huntrule Team
date: 2019-01-16
modified: 2025-10-20
tags:
  - attack.execution
  - attack.t1059.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith:
        - \powershell_ise.exe
        - \powershell.exe
        - \pwsh.exe
    - OriginalFileName:
        - PowerShell_ISE.EXE
        - PowerShell.EXE
        - pwsh.dll
  selection_cli:
    CommandLine|contains|all:
      - new-object
      - net.webclient).
      - download
    CommandLine|contains:
      - string(
      - file(
  condition: all of selection_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL