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Description

The following analytic detects the creation of files in the Windows %startup% folder, a common persistence technique. It leverages the Endpoint.Filesystem data model to identify file creation events in this specific directory. This activity is significant because adversaries often use the startup folder to ensure their malicious code executes automatically upon system boot or user logon. If confirmed malicious, this could allow attackers to maintain persistence on the host, potentially leading to further system compromise and unauthorized access to sensitive information.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-05-19
  • Author: Teoderick Contreras, Splunk
  • ID: 99d157cb-923f-4a00-aee9-1f385412146f

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1547.001 Registry Run Keys / Startup Folder Persistence, Privilege Escalation
T1547 Boot or Logon Autostart Execution Persistence, Privilege Escalation
Kill Chain Phase
  • Installation
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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|tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Filesystem where Filesystem.file_path = "*\\Microsoft\\Windows\\Start Menu\\Programs\\Startup\\*" by Filesystem.file_create_time Filesystem.process_id Filesystem.file_name Filesystem.user Filesystem.file_path Filesystem.process_guid Filesystem.dest 
| `drop_dm_object_name(Filesystem)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_boot_or_logon_autostart_execution_in_startup_folder_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_boot_or_logon_autostart_execution_in_startup_folder_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
  • Filesystem.file_create_time
  • Filesystem.process_id
  • Filesystem.file_name
  • Filesystem.user
  • Filesystem.file_path
  • Filesystem.process_guid
  • Filesystem.dest

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the Filesystem responsible for the changes from your endpoints into the Endpoint datamodel in the Filesystem node.

Known False Positives

Administrators may allow creation of script or exe in this path.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
81.0 90 90 a process dropped a file in %startup% folder in $dest$

: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: 2