name: SLUI Spawning a Process
id: 879c4330-b3e0-11eb-b1b1-acde48001122
version: 1
date: '2021-05-13'
author: Michael Haag, Splunk
type: TTP
datamodel:
- Endpoint
description: The following analytic identifies the Microsoft Software Licensing User
  Interface Tool, `slui.exe`, spawning a child process. This behavior is associated
  with publicly known UAC bypass. `slui.exe` is commonly associated with software
  updates and is most often spawned by `svchost.exe`. The `slui.exe` process should
  not have child processes, and any processes spawning from it will be running with
  elevated privileges. During triage, review the child process and additional parallel
  processes. Identify any file modifications that may have lead to the bypass.
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name=slui.exe
  by Processes.dest Processes.user Processes.parent_process 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)` | `slui_spawning_a_process_filter`'
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.
known_false_positives: Certain applications may spawn from `slui.exe` that are legitimate.
  Filtering will be needed to ensure proper monitoring.
references:
- https://www.exploit-db.com/exploits/46998
- https://www.rapid7.com/db/modules/exploit/windows/local/bypassuac_sluihijack/
- https://www.mandiant.com/resources/shining-a-light-on-darkside-ransomware-operations
tags:
  analytic_story:
  - DarkSide Ransomware
  - Windows Defense Evasion Tactics
  confidence: 90
  context:
  - Source:Endpoint
  - Stage:Privilege Escalation
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.002/slui/windows-sysmon.log
  impact: 70
  kill_chain_phases:
  - Exploitation
  message: A slui process $parent_process_name$ spawning child process $process_name$
    in host $dest$
  mitre_attack_id:
  - T1548.002
  - T1548
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: user
    type: User
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_id
  risk_score: 63
  security_domain: endpoint
  supported_tas:
  - Splunk_TA_microsoft_sysmon
  asset_type: Endpoint