SMB Create Remote File Admin Share — Sigma Rule

Rule metadata and linked tags

Author: Jose Rodriguez (@Cyb3rPandaH), OTR (Open Threat Research). Source status: test; severity: high. Source dates: 2020-08-06 / 2025-10-17.

{
  "product": "windows",
  "service": "security"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 1c82f8a040e9028a36348028bf73a1310919d94b72d338c12343347badb6dca2

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: SMB Create Remote File Admin Share
id: b210394c-ba12-4f89-9117-44a2464b9511
status: test
description: Look for non-system accounts SMB accessing a file with write (0x2) access mask via administrative share (i.e C$).
references:
    - https://github.com/OTRF/ThreatHunter-Playbook/blob/f7a58156dbfc9b019f17f638b8c62d22e557d350/playbooks/WIN-201012004336.yaml
    - https://securitydatasets.com/notebooks/atomic/windows/lateral_movement/SDWIN-200806015757.html?highlight=create%20file
author: Jose Rodriguez (@Cyb3rPandaH), OTR (Open Threat Research)
date: 2020-08-06
modified: 2025-10-17
tags:
    - attack.lateral-movement
    - attack.t1021.002
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 5145
        ShareName|endswith: 'C$'
        AccessMask: '0x2'
    filter_main_subjectusername:
        SubjectUserName|endswith: '$'
    filter_optional_local_ip:
        IpAddress: '::1'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/OTRF/ThreatHunter-Playbook/blob/f7a58156dbfc9b019f17f638b8c62d22e557d350/playbooks/WIN-201012004336.yaml
• https://securitydatasets.com/notebooks/atomic/windows/lateral_movement/SDWIN-200806015757.html?highlight=create%20file