UAC Bypass Attempt via Privileged IFileOperation COM Interface

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UAC Bypass Attempt via Privileged IFileOperation COM Interface

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Identifies attempts to bypass User Account Control (UAC) via DLL side-loading. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

Rule type: eql

Rule indices:

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

Severity: high

Risk score: 73

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: 8

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

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## Setup

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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file where event.type : "change" and process.name : "dllhost.exe" and
  /* Known modules names side loaded into process running with high or system integrity level for UAC Bypass, update here for new modules */
  file.name : ("wow64log.dll", "comctl32.dll", "DismCore.dll", "OskSupport.dll", "duser.dll", "Accessibility.ni.dll") and
  /* has no impact on rule logic just to avoid OS install related FPs */
  not file.path : ("C:\\Windows\\SoftwareDistribution\\*", "C:\\Windows\\WinSxS\\*")

Framework: MITRE ATT&CKTM