Privilege Escalation via Windir Environment Variable

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:

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

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:

https://www.tiraniddo.dev/2017/05/exploiting-environment-variables-in.html

Tags:

Elastic
Host
Windows
Threat Detection
Privilege Escalation

Version: 3 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 7.12.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule query

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

Threat mapping

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Framework: MITRE ATT&CK^TM

Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
Technique:
- Name: Hijack Execution Flow
- ID: T1574
- Reference URL: https://attack.mitre.org/techniques/T1574/

Rule version history

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Version 3 (7.12.0 release)

Formatting only

Version 2 (7.11.2 release)

Formatting only

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