splunk-security_content/detections/endpoint/windows_system_script_proxy_execution_syncappvpublishingserver.yml

name: Windows System Script Proxy Execution Syncappvpublishingserver
id: 8dd73f89-682d-444c-8b41-8e679966ad3c
version: 2
date: '2024-05-18'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the execution of Syncappvpublishingserver.vbs
  via wscript.exe or cscript.exe, which may indicate an attempt to download remote
  files or perform privilege escalation. This detection leverages data from Endpoint
  Detection and Response (EDR) agents, focusing on process names and command-line
  executions. Monitoring this activity is crucial as it can signify malicious use
  of a native Windows script for unauthorized actions. If confirmed malicious, this
  behavior could lead to unauthorized file downloads or elevated privileges, posing
  a significant security risk.
data_source:
- Sysmon EventID 1
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process_name IN ("wscript.exe","cscript.exe")
  Processes.process="*syncappvpublishingserver.vbs*" by Processes.dest Processes.user
  Processes.parent_process_name Processes.process_name Processes.process Processes.process_id
  Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `windows_system_script_proxy_execution_syncappvpublishingserver_filter`'
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: False positives may be present if the vbscript syncappvpublishingserver
  is used for legitimate purposes. Filter as needed. Adding a n; to the command-line
  arguments may help reduce any noise.
references:
- https://lolbas-project.github.io/lolbas/Scripts/Syncappvpublishingserver/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1216/T1216.md#atomic-test-1---syncappvpublishingserver-signed-script-powershell-command-execution
tags:
  analytic_story:
  - Living Off The Land
  asset_type: Endpoint
  confidence: 50
  impact: 60
  message: An instance of $parent_process_name$ spawning $process_name$ was identified
    on endpoint $dest$ by user $user$ attempting to download files or evade critical
    controls.
  mitre_attack_id:
  - T1216
  - T1218
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: parent_process_name
    type: Process
    role:
    - Parent Process
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _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
  risk_score: 30
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: 
      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1216/atomic_red_team/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog
    update_timestamp: true