Disabling User Account Control via Registry Modification

User Account Control (UAC) can help mitigate the impact of malware on Windows hosts. With UAC, apps and tasks always run in the security context of a non-administrator account, unless an administrator specifically authorizes administrator-level access to the system. This rule identifies registry value changes to bypass User Access Control (UAC) protection.

Rule type: eql

Rule indices:

winlogbeat-*
logs-endpoint.events.*
logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

Elastic
Host
Windows
Threat Detection
Privilege Escalation

Version: 4

Rule authors:

Elastic

Rule license: Elastic License v2

Investigation guide

edit

## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule query

edit

registry where event.type == "change" and
  registry.path :
    (
      "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\EnableLUA",
      "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\ConsentPromptBehaviorAdmin",
      "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\PromptOnSecureDesktop"
    ) and
  registry.data.strings : ("0", "0x00000000")

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
Technique:
- Name: Abuse Elevation Control Mechanism
- ID: T1548
- Reference URL: https://attack.mitre.org/techniques/T1548/
Sub-technique:
- Name: Bypass User Account Control
- ID: T1548.002
- Reference URL: https://attack.mitre.org/techniques/T1548/002/
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Abuse Elevation Control Mechanism
- ID: T1548
- Reference URL: https://attack.mitre.org/techniques/T1548/
Sub-technique:
- Name: Bypass User Account Control
- ID: T1548.002
- Reference URL: https://attack.mitre.org/techniques/T1548/002/

« Webshell Detection: Script Process Child of Common Web Processes Startup/Logon Script added to Group Policy Object »