Windows Command-Line Tools Performing Web POST Exfiltration via IWR/curl/wget

title: Windows Command-Line Tools Performing Web POST Exfiltration via IWR/curl/wget
id: ffc15808-eb32-48ee-a25a-3e3af06d7849
status: test
description: This rule flags suspicious process executions on Windows where PowerShell, curl, or wget are invoked with web request parameters consistent with POST-based data exfiltration. It further requires indicative “payload” content such as system and network discovery commands, base64 encoding, or file read/output redirection to local paths. Attackers commonly use legitimate CLI tools to blend into normal activity while transmitting collected data over HTTP(S). The detection relies on Windows process creation telemetry, matching process image names and specific command-line substrings and patterns.
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_susp_data_exfiltration_via_cli.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-08-02
modified: 2025-10-19
tags:
  - attack.execution
  - attack.t1059.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_iwr:
    Image|endswith:
      - \powershell_ise.exe
      - \powershell.exe
      - \pwsh.exe
      - \cmd.exe
    CommandLine|contains:
      - "curl "
      - Invoke-RestMethod
      - Invoke-WebRequest
      - "irm "
      - "iwr "
      - "wget "
    CommandLine|contains|all:
      - " -ur"
      - " -me"
      - " -b"
      - " POST "
  selection_curl:
    Image|endswith: \curl.exe
    CommandLine|contains: --ur
  selection_curl_data:
    CommandLine|contains:
      - " -d "
      - " --data "
  selection_wget:
    Image|endswith: \wget.exe
    CommandLine|contains:
      - --post-data
      - --post-file
  payloads:
    - CommandLine|re:
        - net\s+view
        - sc\s+query
    - CommandLine|contains:
        - Get-Content
        - GetBytes
        - hostname
        - ifconfig
        - ipconfig
        - netstat
        - nltest
        - qprocess
        - systeminfo
        - tasklist
        - ToBase64String
        - whoami
    - CommandLine|contains|all:
        - "type "
        - " > "
        - " C:\\"
  condition: (selection_iwr or all of selection_curl* or selection_wget) and payloads
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: 7d1aaf3d-4304-425c-b7c3-162055e0b3ab
    type: derived