Disabling Windows Defender Security Settings via PowerShell
Elastic Stack Serverless Security
Identifies use of the Set-MpPreference PowerShell command to disable or weaken certain Microsoft Defender settings.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Defense Evasion
Version: 3
Rule authors:
- Elastic
Rule license: Elastic License v2
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.
process where event.type == "start" and
(process.name : ("powershell.exe", "pwsh.exe", "powershell_ise.exe") or process.pe.original_file_name in ("powershell.exe", "pwsh.dll", "powershell_ise.exe")) and
process.args : "Set-MpPreference" and process.args : ("-Disable*", "Disabled", "NeverSend", "-Exclusion*")
Framework: MITRE ATT&CKTM
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Impair Defenses
- ID: T1562
- Reference URL: https://attack.mitre.org/techniques/T1562/
Sub-technique:
- Name: Disable or Modify Tools
- ID: T1562.001
- Reference URL: https://attack.mitre.org/techniques/T1562/001/