Windows Firewall Disabled via PowerShell

Elastic Stack Serverless Security

Identifies when the Windows Firewall is disabled using PowerShell cmdlets, which can help attackers evade network constraints like internet and network lateral communication restrictions.

Rule type: eql

Rule indices:

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

• https://docs.microsoft.com/en-us/powershell/module/netsecurity/set-netfirewallprofile?view=windowsserver2019-ps
• https://www.tutorialspoint.com/how-to-get-windows-firewall-profile-settings-using-powershell
• http://powershellhelp.space/commands/set-netfirewallrule-psv5.php
• http://woshub.com/manage-windows-firewall-powershell/

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Defense Evasion

Version: 4

Rule authors:

• Austin Songer

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.action == "start" and
  (process.name : ("powershell.exe", "pwsh.exe", "powershell_ise.exe") or process.pe.original_file_name == "PowerShell.EXE") and
   process.args : "*Set-NetFirewallProfile*" and
  (process.args : "*-Enabled*" and process.args : "*False*") and
  (process.args : "*-All*" or process.args : ("*Public*", "*Domain*", "*Private*"))

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 System Firewall
  • ID: T1562.004
  • Reference URL: https://attack.mitre.org/techniques/T1562/004/