Windows Winlogon Outbound Network Connections to Public IPs

Flags outbound connections initiated by winlogon.exe to non-local public destination IPs on Windows.

FreeReviewedSigma · Medium · v2

Product: windows
Category: network_connection
Author: Christopher Peacock @securepeacock, SCYTHE @scythe_io (SigmaHQ), DRL 1.1
Published: 2023-04-28
Updated: 2026-07-31

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218.011Rundll32
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

Flags outbound network connections initiated by winlogon.exe where the destination is not within common local, private, link-local, or loopback IP ranges. Attackers can abuse legitimate Windows processes to blend outbound traffic and establish command-and-control or exfiltration channels. This detection relies on Windows network connection telemetry that includes the initiating process image, destination IP, and connection initiation status.

Reporting behind it

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Suspicious Rundll32 Execution of DLL Masquerading as Text File via Blind Eagle (via process_creation)

Suspicious Rundll32 Spawning Injection Target Process via Qakbot (via process_creation)

Malicious Lunar Spider Loader Execution via rundll32 (via process_creation)

Malicious SYSTEM Persistence via Scheduled Task Running rundll32 at Startup (via process_creation)

Malicious Rundll32 Executing Image File as DLL

Suspicious Scheduled Task Executing Rundll32 DLL Export by Ordinal

Malicious Renamed Rundll32 Copied to Temp via Xcopy

Suspicious rundll32 Executing DLL from ProgramData (via process_creation)

Windows Winlogon Outbound Network Connections to Public IPs

Pivot detection · T1218.011 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

windows-winlogon-exe-initiating-outbound-connections-to-public-ips-7610a4ea

title: Windows Winlogon Outbound Network Connections to Public IPs
id: ebf3ca34-f1eb-42ea-ab6b-4df078d5431d
status: test
description: Flags outbound network connections initiated by winlogon.exe where the destination is not within common local, private, link-local, or loopback IP ranges. Attackers can abuse legitimate Windows processes to blend outbound traffic and establish command-and-control or exfiltration channels. This detection relies on Windows network connection telemetry that includes the initiating process image, destination IP, and connection initiation status.
references:
  - https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/network_connection/net_connection_win_winlogon_net_connections.yml
author: Christopher Peacock @securepeacock, SCYTHE @scythe_io, Huntrule Team
date: 2023-04-28
modified: 2024-03-12
tags:
  - attack.execution
  - attack.command-and-control
  - attack.stealth
  - attack.t1218.011
logsource:
  category: network_connection
  product: windows
detection:
  selection:
    Image|endswith: \winlogon.exe
    Initiated: "true"
  filter_main_local_ranges:
    DestinationIp|cidr:
      - 127.0.0.0/8
      - 10.0.0.0/8
      - 172.16.0.0/12
      - 192.168.0.0/16
      - 169.254.0.0/16
      - ::1/128
      - fe80::/10
      - fc00::/7
  condition: selection and not 1 of filter_main_*
falsepositives:
  - Communication to other corporate systems that use IP addresses from public address spaces
level: medium
license: DRL-1.1
related:
  - id: 7610a4ea-c06d-495f-a2ac-0a696abcfd3b
    type: derived

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