Windows Network Connections Initiated by Processes in C:\Users\Public

Flags outbound network connections initiated by a process whose image path is under C:\Users\Public on Windows.

FreeReviewedSigma · Medium · v5
Product
windows
Category
network_connection
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2024-05-31
Updated
2026-07-31
title: Windows Network Connections Initiated by Processes in C:\Users\Public
id: 42b8b261-4875-433b-8982-cf95457d1431
related:
  - id: 7b434893-c57d-4f41-908d-6a17bf1ae98f
    type: derived
  - id: bcb03938-9f8b-487d-8d86-e480691e1d71
    type: derived
status: test
description: This rule flags Windows network connections where the initiating process path contains C:\Users\Public\, indicating execution from a world-writable location. Attackers commonly place payloads in publicly writable directories to increase the chance of successful execution and subsequent command-and-control activity. It relies on Windows network connection telemetry that includes the process image path and whether the connection was initiated.
references:
  - https://docs.google.com/spreadsheets/d/17pSTDNpa0sf6pHeRhusvWG6rThciE8CsXTSlDUAZDyo
  - https://github.com/SigmaHQ/sigma/blob/master/rules-threat-hunting/windows/network_connection/net_connection_win_susp_initaited_public_folder.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2024-05-31
tags:
  - attack.command-and-control
  - attack.t1105
  - detection.threat-hunting
logsource:
  category: network_connection
  product: windows
detection:
  selection:
    Initiated: "true"
    Image|contains: :\Users\Public\
  filter_optional_ibm:
    Image|contains: :\Users\Public\IBM\ClientSolutions\Start_Programs\
  condition: selection and not 1 of filter_optional_*
falsepositives:
  - Likely from legitimate third party application that execute from the "Public" directory.
level: medium
license: DRL-1.1