SCOM monitor script for checking firewall status. Requires something like the PowerShell script monitor MP by Wei Lim: https://gallery.technet.microsoft.com/Sample-Management-Pack-17b76379

CheckFirewall.ps1

$API = New-Object -ComObject "MOM.ScriptAPI" -ErrorAction Stop
$PropertyBag = $API.CreatePropertyBag()

$Profiles = @{'Domain' = '0'; 'Standard' = '0'; 'Public' = '0'}
$Profiles.Domain = (Get-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile' -Name EnableFirewall).EnableFirewall
$Profiles.Standard = (Get-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile' -Name EnableFirewall).EnableFirewall
$Profiles.Public = (Get-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\PublicProfile' -Name EnableFirewall).EnableFirewall

if ($Profiles.Values -contains 0)
{
    $PropertyBag.AddValue('State', 1)
    $API.LogScriptEvent("FirewallState.ps1", 1009, 0, "One or more firewall profiles are disabled, see property bag for details.")
}
else
{
    $PropertyBag.AddValue('State', 0)
    $API.LogScriptEvent("FirewallState.ps1", 1000, 0, "All firewall profiles are enabled.")
}

foreach ($key in $Profiles.Keys)
{
    $PropertyBag.AddValue($key, $($Profiles.Item($key)))
}

$PropertyBag