Microsoft Defender Antivirus
TMA-DEFENDER-1.6.1.9
Ensure 'Configure Attack Surface Reduction rules: Set the state for each ASR rule' is set to 'd3e037e1-3eb8-44c8-a917- 57927947596d:1'
Description
This rule prevents scripts from launching potentially malicious downloaded content. Rule ID and name: - d3e037e1-3eb8-44c8-a917-57927947596d (Block JavaScript or VBScript from launching downloaded executable content) The recommended state for this setting is: d3e037e1-3eb8-44c8-a917- 57927947596d:1 (Block). Rationale: Attack surface reduction helps prevent actions and apps that are typically used by exploit-seeking malware to infect machines. Malware written in JavaScript or VBScript often acts as a downloader to fetch and launch other malware from the Internet. 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\Rules:d3e037e1-3eb8-44c8-a917-57927947596d (REG_SZ); compliant when it is 1.
How it is checked
Audit method: Windows registry
$v = (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules' -Name 'd3e037e1-3eb8-44c8-a917-57927947596d' -ErrorAction SilentlyContinue).'d3e037e1-3eb8-44c8-a917-57927947596d'; if ($null -eq $v) { 'unset' } elseif (($null -ne $v -and @('1') -contains "$v")) { 'compliant' } else { "non-compliant: $v" }- Expected output
compliant
How it is fixed
Fix method: Guidance or infrastructure patch
Configure through Group Policy: Computer Configuration\Policies\Administrative Templates\Windows Components\Microsoft Defender Antivirus\Microsoft Defender Exploit Guard\Attack Surface Reduction\Configure Attack Surface Reduction rules: Set the state for each ASR rule = d3e037e1-3eb8-44c8-a917-57927947596d with a value of 1. Test in audit mode (2) first. Local alternative (writes Defender preferences, not the Group Policy value this audit reads): Add-MpPreference -AttackSurfaceReductionRules_Ids d3e037e1-3eb8-44c8-a917-57927947596d -AttackSurfaceReductionRules_Actions 1
Properties
- Operating systems
- Any
- Tags
- defenderantiviruscis-l1
- Reference
- CIS Microsoft Defender Antivirus Benchmark v1.0.0 - 1.6.1.9 Ensure 'Configure Attack Surface Reduction rules: Set the state for each ASR rule' is set to 'd3e037e1-3eb8-44c8-a917- 57927947596d:1'
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target defender