Unmount Share Via Net.EXE — Sigma Rule

Rule metadata and linked tags

Author: oscd.community, @redcanary, Zach Stanford @svch0st. Source status: test; severity: low. Source dates: 2020-10-08 / 2023-02-21.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 7da867e3d7644428bb6af65906aedb42cc090078ecaab1cb5deb3e25b611cc61

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: Unmount Share Via Net.EXE
id: cb7c4a03-2871-43c0-9bbb-18bbdb079896
status: test
description: Detects when when a mounted share is removed. Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.005/T1070.005.md
author: oscd.community, @redcanary, Zach Stanford @svch0st
date: 2020-10-08
modified: 2023-02-21
tags:
    - attack.stealth
    - attack.t1070.005
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              - '\net.exe'
              - '\net1.exe'
        - OriginalFileName:
              - 'net.exe'
              - 'net1.exe'
    selection_cli:
        CommandLine|contains|all:
            - 'share'
            - '/delete'
    condition: all of selection*
falsepositives:
    - Administrators or Power users may remove their shares via cmd line
level: low

Original YAML and metadata in JSON

False positives

• Administrators or Power users may remove their shares via cmd line

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.005/T1070.005.md