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Description

The following analytic detects the creation of local administrator accounts using the net.exe command to mitigate the risks associated with unauthorized access and prevent further damage to the environment by responding to potential threats earlier and taking appropriate actions to protect the organization's systems and data. This detection is made by a Splunk query to search for processes with the name net.exe or net1.exe that include the "/add" parameter and have specific keywords related to administrator accounts in their process name. This detection is important because the creation of unauthorized local administrator accounts might indicate that an attacker has successfully created a new administrator account and is trying to gain persistent access to a system or escalate their privileges for data theft, or other malicious activities. False positives might occur since there might be legitimate uses of the net.exe command and the creation of administrator accounts in certain circumstances. You must consider the context of the activity and other indicators of compromise before taking any action. For next steps, review the details of the identified process, including the user, parent process, and parent process name. Examine any relevant on-disk artifacts and look for concurrent processes to determine the source of the attack.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-09-08
  • Author: Bhavin Patel, Splunk
  • ID: b89919ed-fe5f-492c-b139-151bb162040e

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1136.001 Local Account Persistence
T1136 Create Account Persistence
Kill Chain Phase
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count values(Processes.user) as user values(Processes.parent_process) as parent_process values(parent_process_name) as parent_process_name min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=net.exe OR Processes.process_name=net1.exe) AND Processes.process=*/add* AND (Processes.process=*administrators* OR Processes.process=*administratoren* OR Processes.process=*administrateurs* OR Processes.process=*administrador* OR Processes.process=*amministratori* OR Processes.process=*administratorer*) by Processes.process Processes.process_name Processes.dest 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `create_local_admin_accounts_using_net_exe_filter`

Macros

The SPL above uses the following Macros:

:information_source: create_local_admin_accounts_using_net_exe_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _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

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Administrators often leverage net.exe to create admin accounts.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
30.0 50 60 An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to add a user to the local Administrators group.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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: 6