Firewall Rule Deleted Via Netsh.EXE

A Sigma rule for process creation on Windows, by frack113.

medium 1 ATT&CK technique 2 programs it names 2 everyday examples trip it

What it looks for

its detection, as SigmaHQ writes it

detection:
  filter_optional_avast:
    CommandLine|contains: 'advfirewall firewall delete rule name="Avast Antivirus Admin Client"'
    ParentImage|endswith: '\instup.exe'
  filter_optional_dropbox:
    CommandLine|contains: 'name=Dropbox'
    ParentImage|endswith: '\Dropbox.exe'
  selection_cli:
    CommandLine|contains|all:
      - 'firewall'
      - 'delete '
  selection_img:
    - Image|endswith: '\netsh.exe'
    - OriginalFileName: 'netsh.exe'
  condition: all of selection_* and not 1 of filter_optional_*

The rule’s detection, its selections and fields in order of name. The whole rule, with its references and false positives, is on SigmaHQ, by frack113, under the Detection Rule License 1.1. CmdID evaluates it on a command line alone: a test on what a command line cannot show, such as the parent process or the user, is not met.

Command lines that trip it

everyday examples from tldr-pages, CC BY 4.0, each read by CmdID

To delete a connection security rule by its name, run the following command on the page for netsh advfirewall

netsh advfirewall consec delete rule name="RuleName"Identify

To remove a specific firewall rule by name, run the following command on the page for netsh advfirewall

netsh advfirewall firewall delete rule name="MyRule"Identify

Programs and files it names

their pages here

netsh.exeDropbox.exe

ATT&CK

the techniques it is tagged with

T1686.003Disable or Modify System Firewall: Windows Host Firewall

Firewall Rule Deleted Via Netsh.EXE

What it looks for

Command lines that trip it

Programs and files it names

ATT&CK

Other rules for T1686.003 Disable or Modify System Firewall: Windows Host Firewall