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.
- Product
- windows
- Category
- network_connection
- Author
- Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2025-11-19
- Updated
- 2026-07-31
ATT&CK techniques
Execution → C2Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
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
Changelog
v2- v2Candidate ingested via manual entry.2026-07-31
- v1No 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.
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