Firewall deactivation (PowerShell)

Status: experimental
Severity: high
Log source: category ['ps_module', 'ps_classic_script', 'ps_script'], product windows
Author: mdecrevoisier
Source: github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker disabled the Windows Firewall to evade defense.

Known false positives

None

MITRE ATT&CK coverage

Tactic	Techniques
Defense Impairment	`T1685` Disable or Modify Tools `T1686` Disable or Modify System Firewall

Telemetry coverage

Provider	Record / event type
PowerShell	Event ID 4103: Payload Context: ContextInfo User Data: UserData.
PowerShell	Event ID 4104: Creating Scriptblock text (MessageNumber of MessageTotal).
PowerShell	Event ID 800

Rule body

title: Firewall deactivation (PowerShell)
description: Detects scenarios where an attacker disabled the Windows Firewall to evade defense.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0005-Defense%20Evasion/T1562.004-Impair%20Defenses-Disable%20or%20Modify%20System%20Firewall
- https://www.alitajran.com/disable-windows-firewall-with-powershell/
- https://docs.microsoft.com/en-us/powershell/module/netsecurity/set-netfirewallprofile?view=windowsserver2019-ps
tags:
- attack.defense_evasion
- attack.t1562.004
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category:
    - ps_module
    - ps_classic_script
    - ps_script
detection: # full command: "Set-NetFirewallProfile -Profile Domain, Public, Private -Enabled False"
  selection_powershell_native:
    EventID: 800
    EventData|contains|all:
      - Set-NetFirewallProfile
      - Profile
      - Enabled
      - 'False'

  selection_powershell_modern:
    EventID: 4103
    Payload|contains|all:
      - Set-NetFirewallProfile
      - Profile
      - Enabled
      - 'False'

  selection_powershell_block:
    EventID: 4104
    ScriptBlockText|contains|all:
      - Set-NetFirewallProfile
      - Profile
      - Enabled
      - 'False'

  condition: selection_powershell_native or selection_powershell_modern or selection_powershell_block
falsepositives:
- None
level: high

Stages and Predicates

Stage 0: `condition`

selection_powershell_native or selection_powershell_modern or selection_powershell_block

Stage 1: `selection_powershell_native`

selection_powershell_native:
  EventID: 800
  EventData|contains|all:
    - Set-NetFirewallProfile
    - Profile
    - Enabled
    - 'False'

Stage 2: `selection_powershell_modern`

selection_powershell_modern:
  EventID: 4103
  Payload|contains|all:
    - Set-NetFirewallProfile
    - Profile
    - Enabled
    - 'False'

Stage 3: `selection_powershell_block`

selection_powershell_block:
  EventID: 4104
  ScriptBlockText|contains|all:
    - Set-NetFirewallProfile
    - Profile
    - Enabled
    - 'False'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventData`	match	`Enabled` `False` `Profile` `Set-NetFirewallProfile`	`field:"EventData" kind:match`
`Payload`	match	`Enabled` `False` `Profile` `Set-NetFirewallProfile`	`field:"Payload" kind:match`
`ScriptBlockText`	match	`Enabled` `False` `Profile` `Set-NetFirewallProfile`	`field:"ScriptBlockText" kind:match`

Firewall deactivation (PowerShell)

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_powershell_native

Stage 2: selection_powershell_modern

Stage 3: selection_powershell_block

Indicators

Stage 0: `condition`

Stage 1: `selection_powershell_native`

Stage 2: `selection_powershell_modern`

Stage 3: `selection_powershell_block`