Privilege Escalation via Windir Environment Variable

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Privilege Escalation via Windir Environment Variable

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Identifies a privilege escalation attempt via a rogue Windows directory (Windir) environment variable. This is a known primitive that is often combined with other vulnerabilities to elevate privileges.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*
  • endgame-*
  • logs-windows.sysmon_operational-*

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:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Privilege Escalation
  • Data Source: Elastic Endgame
  • Data Source: Elastic Defend
  • Data Source: Sysmon

Version: 105

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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registry where host.os.type == "windows" and registry.path : (
    "HKEY_USERS\\*\\Environment\\windir",
    "HKEY_USERS\\*\\Environment\\systemroot",
    "HKU\\*\\Environment\\windir",
    "HKU\\*\\Environment\\systemroot",
    "\\REGISTRY\\USER\\*\\Environment\\windir",
    "\\REGISTRY\\USER\\*\\Environment\\systemroot"
    ) and
 not registry.data.strings : ("C:\\windows", "%SystemRoot%")

Framework: MITRE ATT&CKTM