fodhelper_uac_bypass.yml

name: FodHelper UAC Bypass
id: 909f8fd8-7ac8-11eb-a1f3-acde48001122
version: 1
date: '2021-03-01'
author: Michael Haag, Splunk
type: batch
datamodel:
- Endpoint
description: 'Fodhelper.exe has a known UAC bypass as it attempts to look for specific
  registry keys upon execution, that do not exist. Therefore, an attacker can write
  its malicious commands in these registry keys to be executed by fodhelper.exe with
  the highest privilege. \

  1. `HKCU:\Software\Classes\ms-settings\shell\open\command`\

  1. `HKCU:\Software\Classes\ms-settings\shell\open\command\DelegateExecute`\

  1. `HKCU:\Software\Classes\ms-settings\shell\open\command\(default)`\

  Upon triage, fodhelper.exe will have a child process and read access will occur
  on the registry keys. Isolate the endpoint and review parallel processes for additional
  behavior.'
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name=fodhelper.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)` | `fodhelper_uac_bypass_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: Limited to no false positives are expected.
references:
- https://blog.malwarebytes.com/malwarebytes-news/2021/02/lazyscripter-from-empire-to-double-rat/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1548.002/T1548.002.md
- https://github.com/gushmazuko/WinBypass/blob/master/FodhelperBypass.ps1
- https://attack.mitre.org/techniques/T1548/002
tags:
  analytic_story:
  - Windows Defense Evasion Tactics
  automated_detection_testing: passed
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.002/atomic_red_team/windows-sysmon.log
  kill_chain_phases:
  - Exploitation
  - Privilege Escalation
  mitre_attack_id:
  - T1112
  - T1548.002
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.parent_process_name
  - Processes.dest
  - Processes.user
  - Processes.parent_process
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_id
  security_domain: endpoint