Windows: MSPUB.EXE Downloading Arbitrary Files via HTTP/FTP URIs

title: "Windows: MSPUB.EXE Downloading Arbitrary Files via HTTP/FTP URIs"
id: 314e0b23-ee15-44b6-8d26-864f2fee9b83
status: test
description: This rule identifies process executions of Microsoft Publisher (MSPUB.EXE) where the command line contains HTTP or FTP URLs, indicating an attempt to download an arbitrary file. Attackers can use trusted Windows applications to blend in with normal activity while retrieving payloads or secondary content. The detection relies on Windows process creation telemetry capturing the executable path/name and the full command line.
references:
  - https://github.com/LOLBAS-Project/LOLBAS/pull/238/files
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_mspub_download.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-08-19
modified: 2023-02-08
tags:
  - attack.execution
  - attack.stealth
  - attack.t1218
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \MSPUB.exe
    - OriginalFileName: MSPUB.exe
  selection_cli:
    CommandLine|contains:
      - ftp://
      - http://
      - https://
  condition: all of selection_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 3b3c7f55-f771-4dd6-8a6e-08d057a17caf
    type: derived