DNS Query by Finger Utility

Detects DNS queries made by the finger utility, which can be abused by threat actors to retrieve remote commands for execution on Windows devices. In one ClickFix malware campaign, adversaries leveraged the finger protocol to fetch commands from a remote server. Since the finger utility is not commonly used in modern Windows environments, its presence already raises suspicion. Investigating such DNS queries can also help identify potential malicious infrastructure used by threat actors for command and control (C2) communication.

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Detection logic

selection

Image|endswith: \finger.exe

Condition

selection

Raw YAML

title: DNS Query by Finger Utility
id: c082c2b0-525b-4dbc-9a26-a57dc4692074
related:
    - id: 2fdaf50b-9fd5-449f-ba69-f17248119af6
      type: similar
    - id: af491bca-e752-4b44-9c86-df5680533dbc
      type: similar
status: experimental
description: |
    Detects DNS queries made by the finger utility, which can be abused by threat actors to retrieve remote commands for execution on Windows devices.
    In one ClickFix malware campaign, adversaries leveraged the finger protocol to fetch commands from a remote server.
    Since the finger utility is not commonly used in modern Windows environments, its presence already raises suspicion.
    Investigating such DNS queries can also help identify potential malicious infrastructure used by threat actors for command and control (C2) communication.
references:
    - https://www.bleepingcomputer.com/news/security/decades-old-finger-protocol-abused-in-clickfix-malware-attacks/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-11-19
tags:
    - attack.command-and-control
    - attack.t1071.004
    - attack.execution
    - attack.t1059.003
logsource:
    product: windows
    category: dns_query
detection:
    selection:
        Image|endswith: '\finger.exe'
    condition: selection
falsepositives:
    - Unlikely
level: high