Detection rules › Sigma

New User Created Via Net.EXE

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
Endgame, JHasenbusch (adapted to Sigma for oscd.community)
Source
github.com/SigmaHQ/sigma

Identifies the creation of local users via the net.exe command.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1136.001 Create Account: Local Account

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: New User Created Via Net.EXE
id: cd219ff3-fa99-45d4-8380-a7d15116c6dc
related:
    - id: b9f0e6f5-09b4-4358-bae4-08408705bd5c
      type: similar
status: test
description: Identifies the creation of local users via the net.exe command.
references:
    - https://eqllib.readthedocs.io/en/latest/analytics/014c3f51-89c6-40f1-ac9c-5688f26090ab.html
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1136.001/T1136.001.md
author: Endgame, JHasenbusch (adapted to Sigma for oscd.community)
date: 2018-10-30
modified: 2023-02-21
tags:
    - attack.persistence
    - attack.t1136.001
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:
            - 'user'
            - 'add'
    condition: all of selection_*
falsepositives:
    - Legitimate user creation.
    - Better use event IDs for user creation rather than command line rules.
level: medium

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img

selection_img:
    - Image|endswith:
          - '\net.exe'
          - '\net1.exe'
    - OriginalFileName:
          - 'net.exe'
          - 'net1.exe'

Stage 2: selection_cli

selection_cli:
    CommandLine|contains|all:
        - 'user'
        - 'add'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • add corpus 34 (sigma 26, splunk 4, chronicle 2, kusto 2)
  • user corpus 17 (sigma 11, splunk 4, chronicle 2)
Imageends_with
  • \net.exe corpus 49 (sigma 49)
  • \net1.exe corpus 47 (sigma 47)
OriginalFileNameeq
  • net.exe corpus 28 (sigma 19, elastic 7, splunk 2)
  • net1.exe corpus 44 (sigma 19, splunk 19, elastic 6)