Detection rules › Sigma

Firewall rule any/any created

Status
experimental
Severity
high
Log source
product windows, service firewall-as
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where a firewall rule any/any is added to allow any incoming or outgoing traffic.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Firewall rule any/any created
description: Detects scenarios where a firewall rule any/any is added to allow any incoming or outgoing traffic.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0005-Defense%20Evasion/T1562.004-Impair%20Defenses-Disable%20or%20Modify%20System%20Firewall
- https://kb.eventtracker.com/evtpass/evtPages/EventId_2004_Microsoft-Windows-WindowsFirewallwithAdvancedS_65673.asp
tags:
- attack.defense_evasion
- attack.t1562.004
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  service: firewall-as
detection:
  selection_basic:
    EventID:
      - 2004  # new rule created
      - 2005  # existing rule modified
    Action: 3 # allow

  selection_any_port:
    LocalPorts: '*'
    RemotePorts: '*'

  selection_any_address:
    LocalAddresses: '*' 
    RemoteAddresses: '*'

  condition: selection_basic and (selection_any_port or selection_any_address)
falsepositives:
- Firewall rule debugging
level: high

Stages and Predicates

Stage 0: condition

selection_basic and (selection_any_port or selection_any_address)

Stage 1: selection_basic

selection_basic:
  EventID:
    - 2004
    - 2005
  Action: 3

Stage 2: selection_any_port

selection_any_port:
  LocalPorts: '*'
  RemotePorts: '*'

Stage 3: selection_any_address

selection_any_address:
  LocalAddresses: '*'
  RemoteAddresses: '*'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Actioneq
  • 3 corpus 2 (sigma 2)
LocalAddresseswildcard
  • *
LocalPortswildcard
  • *
RemoteAddresseswildcard
  • *
RemotePortswildcard
  • *