Windows Network Connection Initiated by finger.exe

Alerts on Windows network connections started by finger.exe, an unusual utility that can support remote command retrieval.

FreeReviewedSigma · High · v2

Product: windows
Category: network_connection
Author: Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2025-11-19
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Execution → C2

Recon
Resource Dev
Initial Access
Execution
- T1059.003Windows Command Shell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.004DNS
Exfiltration
Impact

What it detects

This rule flags network connections where the initiating process is finger.exe on Windows. Attackers can abuse the legacy finger protocol to reach out to remote infrastructure for commands or related execution steps. It relies on network connection telemetry that includes process context (specifically the initiating process image ending with \finger.exe).

Reporting behind it

Related detections9 linkedT1059.003 — drag to rearrange

Windows DNS Queries Triggered by finger.exe

Suspicious Script Download via Curl and PowerShell by Dohdoor

Suspicious IP Release and Renew via Minimized cmd During Driver Install

Malicious IIS Worker Spawning nslookup via WS_FTP Deserialization

Malicious Metasploit Reverse Shell Injection in SQL Server (via process_creation)

Suspicious Fake Crypto Wallet Installer Batch Script Staging (via file_event)

Obfuscated Encoded PowerShell Payload Deployed via Process Execution (via process_creation)

DoT (DNS Over TLS) Activation - Command (via process_creation)

Operator Bloopers Cobalt Strike Modules

Windows Network Connection Initiated by finger.exe

Pivot detection · T1059.003 · 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-network-connection-via-finger-exe-2fdaf50b

title: Windows Network Connection Initiated by finger.exe
id: de23b6fd-12c7-4b36-8605-d6e64ceb8cbd
related:
  - id: c082c2b0-525b-4dbc-9a26-a57dc4692074
    type: similar
  - id: af491bca-e752-4b44-9c86-df5680533dbc
    type: similar
  - id: 2fdaf50b-9fd5-449f-ba69-f17248119af6
    type: derived
status: experimental
description: This rule flags network connections where the initiating process is finger.exe on Windows. Attackers can abuse the legacy finger protocol to reach out to remote infrastructure for commands or related execution steps. It relies on network connection telemetry that includes process context (specifically the initiating process image ending with \finger.exe).
references:
  - https://www.bleepingcomputer.com/news/security/decades-old-finger-protocol-abused-in-clickfix-malware-attacks/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/network_connection/net_connection_win_finger.yml
author: Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-11-19
tags:
  - attack.command-and-control
  - attack.t1071.004
  - attack.execution
  - attack.t1059.003
logsource:
  category: network_connection
  product: windows
detection:
  selection:
    Initiated: "true"
    Image|endswith: \finger.exe
  condition: selection
falsepositives:
  - Unlikely
level: high
license: DRL-1.1

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL