Privilege Escalation via Windir Environment Variableedit

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.*

Severity: high

Risk score: 73

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: 100 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 8.5.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule queryedit

registry where registry.path : ("HKEY_USERS\\*\\Environment\\windir",
"HKEY_USERS\\*\\Environment\\systemroot") and not
registry.data.strings : ("C:\\windows", "%SystemRoot%")

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 100 (8.5.0 release)
  • Updated query, changed from:

    registry where registry.path : ("HKEY_USERS\\*\\Environment\\windir",
    "HKEY_USERS\\*\\Environment\\systemroot") and not
    registry.data.strings : ("C:\\windows", "%SystemRoot%")
Version 5 (8.4.0 release)
  • Formatting only
Version 4 (8.1.0 release)
  • Formatting only
Version 3 (7.12.0 release)
  • Formatting only
Version 2 (7.11.2 release)
  • Formatting only