splunk-security_content/docs/_posts/2021-09-27-logon_script_event_trigger_execution.md

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title	excerpt	categories	last_modified_at	toc	toc_label	tags
Logon Script Event Trigger Execution	Boot or Logon Initialization Scripts, Logon Script (Windows)	Endpoint	2021-09-27	true		Boot or Logon Initialization Scripts Persistence Privilege Escalation Logon Script (Windows) Persistence Privilege Escalation Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

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Description

This search is to detect a suspicious modification of registry entry to persist and gain privilege escalation upon booting up of compromised host. This technique was seen in several APT and malware where it modify UserInitMprLogonScript registry entry to its malicious payload to be executed upon boot up of the machine.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-09-27
• Author: Teoderick Contreras, Splunk
• ID: 4c38c264-1f74-11ec-b5fa-acde48001122

ATT&CK

ID	Technique	Tactic
T1037	Boot or Logon Initialization Scripts	Persistence, Privilege Escalation

| T1037.001 | Logon Script (Windows) | Persistence, Privilege Escalation |

Search

| tstats `security_content_summariesonly` count  min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where Registry.registry_path IN ("*\\Environment\\UserInitMprLogonScript") by Registry.dest  Registry.user Registry.registry_path Registry.registry_key_name Registry.registry_value_name 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `drop_dm_object_name(Registry)` 
| `logon_script_event_trigger_execution_filter`

Associated Analytic Story

• Windows Persistence Techniques
• Windows Privilege Escalation

How To Implement

To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.

Required field

• _time
• Registry.dest
• Registry.user
• Registry.registry_path
• Registry.registry_key_name
• Registry.registry_value_name

Kill Chain Phase

• Exploitation

Known False Positives

unknown

RBA

Risk Score	Impact	Confidence	Message
80.0	80	100	modified/added/deleted registry entry Registry.registry_path in dest

Reference

• https://attack.mitre.org/techniques/T1037/001

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

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1037.001/logonscript_reg/sysmon.log

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