Whoami.EXE Execution With Output Option — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-02-28 / 2023-12-04.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b1c66c34acc77754685d25cb8456095947ebdebaeca01ac303507c826222e174

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Whoami.EXE Execution With Output Option
id: c30fb093-1109-4dc8-88a8-b30d11c95a5d
status: test
description: Detects the execution of "whoami.exe" with the "/FO" flag to choose CSV as output format or with redirection options to export the results to a file for later use.
references:
    - https://brica.de/alerts/alert/public/1247926/agent-tesla-keylogger-delivered-inside-a-power-iso-daa-archive/
    - https://app.any.run/tasks/7eaba74e-c1ea-400f-9c17-5e30eee89906/
    - https://www.youtube.com/watch?v=DsJ9ByX84o4&t=6s
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2023-02-28
modified: 2023-12-04
tags:
    - attack.discovery
    - attack.t1033
    - car.2016-03-001
logsource:
    category: process_creation
    product: windows
detection:
    selection_main_img:
        - Image|endswith: '\whoami.exe'
        - OriginalFileName: 'whoami.exe'
    selection_main_cli:
        CommandLine|contains:
            - ' /FO CSV'
            - ' -FO CSV'
    selection_special:
        CommandLine|contains: 'whoami*>'
    condition: all of selection_main_* or selection_special
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://brica.de/alerts/alert/public/1247926/agent-tesla-keylogger-delivered-inside-a-power-iso-daa-archive/
• https://app.any.run/tasks/7eaba74e-c1ea-400f-9c17-5e30eee89906/
• https://www.youtube.com/watch?v=DsJ9ByX84o4&t=6s