Ensure 'Configure Attack Surface Reduction rules' is set to 'Enabled'

HighLevel 1Automateddefender

Description

This policy setting controls the state for the Attack Surface Reduction (ASR) rules. The recommended state for this setting is: Enabled. Rationale: Attack surface reduction helps prevent actions and apps that are typically used by exploit-seeking malware to infect machines. Audit reads the Group Policy registry value and prints 'compliant', 'unset' (policy not configured, reported as FAIL) or the non-compliant value. Registry value: HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR:ExploitGuard_ASR_Rules (REG_DWORD); compliant when it is 1. Remediation writes 1 locally; in a domain set it through the ADMX so Group Policy does not revert it.

How it is checked

Audit method: Windows registry

registry

$v = (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR' -Name 'ExploitGuard_ASR_Rules' -ErrorAction SilentlyContinue).'ExploitGuard_ASR_Rules'; if ($null -eq $v) { 'unset' } elseif (($null -ne $v -and @(1) -contains [int64]$v)) { 'compliant' } else { "non-compliant: $v" }

Expected output: compliant

How it is fixed

Fix method: Shell command

shell

$p = 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR'; if (-not (Test-Path -Path $p)) { New-Item -Path $p -Force | Out-Null }; New-ItemProperty -Path $p -Name 'ExploitGuard_ASR_Rules' -Value 1 -PropertyType DWord -Force | Out-Null

Properties

Operating systems: Any
Tags: defenderantiviruscis-l1
Reference: CIS Microsoft Defender Antivirus Benchmark v1.0.0 - 1.6.1.1 Ensure 'Configure Attack Surface Reduction rules' is set to 'Enabled'

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target defender