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Description

This analytic will identify a suspicious command-line that disables a user account using the net.exe utility native to Windows. This technique may used by the adversaries to interrupt availability of such users to do their malicious act.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint- Datasource: Splunk Add-on for Sysmon
  • Last Updated: 2021-05-04
  • Author: Teoderick Contreras, Splunk
  • ID: c0325326-acd6-11eb-98c2-acde48001122

Annotations

ATT&CK
ID Technique Tactic
T1531 Account Access Removal Impact
Kill Chain Phase
  • Exploitation
NIST
CIS20
CVE 
1
2
3
4
5
6

| tstats `security_content_summariesonly` values(Processes.process) as process values(Processes.parent_process) as parent_process values(Processes.process_id) as process_id count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_net` AND Processes.process="*user*" AND Processes.process="*/active:no*" by  Processes.process_name Processes.original_file_name Processes.dest Processes.user Processes.parent_process_name 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `disabling_net_user_account_filter`

Macros

The SPL above uses the following Macros:

Note that disabling_net_user_account_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.original_file_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_path
  • Processes.process_path
  • Processes.parent_process_id

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Known False Positives

unknown

Associated Analytic story

RBA

Risk Score Impact Confidence Message
42.0 70 60 An instance of $parent_process_name$ spawning $process_name$ was identified disabling a user account on endpoint $dest$ by user $user$.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 2