Suspicious Invoke-WebRequest Execution — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2022-08-02 / 2025-07-18.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 0c9f9c712230b6c9ca0bc166b01d9475c6669f51ed0fd1717fadf2884f0f99bd

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: Suspicious Invoke-WebRequest Execution
id: 5e3cc4d8-3e68-43db-8656-eaaeefdec9cc
related:
    - id: e218595b-bbe7-4ee5-8a96-f32a24ad3468
      type: derived
status: test
description: Detects a suspicious call to Invoke-WebRequest cmdlet where the and output is located in a suspicious location
references:
    - https://www.sentinelone.com/blog/living-off-windows-defender-lockbit-ransomware-sideloads-cobalt-strike-through-microsoft-security-tool/
author: Nasreddine Bencherchali (Nextron Systems)
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:
            # These are all aliases of Invoke-WebRequest
            - '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

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.sentinelone.com/blog/living-off-windows-defender-lockbit-ransomware-sideloads-cobalt-strike-through-microsoft-security-tool/