name: Windows System Script Proxy Execution Syncappvpublishingserver
id: 8dd73f89-682d-444c-8b41-8e679966ad3c
version: 1
date: '2022-09-26'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic identifies the abuse of Syncappvpublishingserver.vbs,
  which is a native script on Windows that may be utilized to download remote files
  or perform privilege escalation.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    CommandLine: '*syncappvpublishingserver.vbs*'
    Image|endswith:
    - wscript.exe
    - cscript.exe
  condition: selection1
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: 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
  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