Windows PowerShell Invoke-WebRequest Download to Suspicious Paths

Alert when PowerShell uses Invoke-WebRequest/aliases with download flags and targets suspicious file locations.

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windows-powershell-invoke-webrequest-download-to-suspicious-paths-5e3cc4d8

title: Windows PowerShell Invoke-WebRequest Download to Suspicious Paths
id: c9b27984-a687-4f9d-9ff6-4f165907334e
related:
  - id: e218595b-bbe7-4ee5-8a96-f32a24ad3468
    type: derived
  - id: 5e3cc4d8-3e68-43db-8656-eaaeefdec9cc
    type: derived
status: test
description: This rule flags Windows process executions where a PowerShell-related binary (PowerShell ISE, PowerShell, or pwsh) runs a command that includes Invoke-WebRequest (or aliases like curl/wget/iwr) and output/download flags (-ur, -o). It also requires the command line to reference writing or directing content to commonly abused locations such as AppData, Desktop, Temp, Public, or paths under :\Windows. This behavior is significant because it can indicate scripted download-and-execute stages used to bring attacker-controlled payloads onto a host. It relies on process creation telemetry, including the image name and full command line.
references:
  - https://www.sentinelone.com/blog/living-off-windows-defender-lockbit-ransomware-sideloads-cobalt-strike-through-microsoft-security-tool/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_powershell_invoke_webrequest_download.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-08-02
modified: 2025-07-18
tags:
  - attack.command-and-control
  - attack.t1105
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_commands:
    CommandLine|contains:
      - "curl "
      - Invoke-WebRequest
      - "iwr "
      - "wget "
  selection_flags:
    CommandLine|contains:
      - " -ur"
      - " -o"
  selection_susp_locations:
    CommandLine|contains:
      - \AppData\
      - \Desktop\
      - \Temp\
      - \Users\Public\
      - "%AppData%"
      - "%Public%"
      - "%Temp%"
      - "%tmp%"
      - :\Windows\
  condition: all of selection_*
falsepositives:
  - Unknown
level: high
license: DRL-1.1

What it detects

This rule flags Windows process executions where a PowerShell-related binary (PowerShell ISE, PowerShell, or pwsh) runs a command that includes Invoke-WebRequest (or aliases like curl/wget/iwr) and output/download flags (-ur, -o). It also requires the command line to reference writing or directing content to commonly abused locations such as AppData, Desktop, Temp, Public, or paths under :\Windows. This behavior is significant because it can indicate scripted download-and-execute stages used to bring attacker-controlled payloads onto a host. It relies on process creation telemetry, including the image name and full command line.

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.