Disabling User Account Control via Registry Modification

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Disabling User Account Control via Registry Modification

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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: 5 minutes

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 (version history)

Added (Elastic Stack release): 7.12.0

Last modified (Elastic Stack release): 8.2.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guide

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## 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

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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\\PromptOnSecure
Desktop" ) and registry.data.strings : ("0", "0x00000000")

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 4 (8.2.0 release)
  • Formatting only
Version 3 (8.1.0 release)
  • Updated query, changed from:

    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\\PromptOnSecure
    Desktop" ) and registry.data.strings : "0"
Version 2 (7.15.0 release)
  • Formatting only