Ensure 'Configure the 'Block at First Sight' feature' is set to 'Enabled'

MediumLevel 1Automatedintune-defender

Description

This policy setting configures whether the device checks (in real time) with the Microsoft Active Protection Service (MAPS) before allowing certain content to be run or accessed. The block at first sight feature works when Microsoft Defender Antivirus encounters a suspicious but undetected file. It then queries the Microsoft cloud protection backend and applies heuristics, machine learning, and automated analysis of the file to determine whether the files are malicious. The recommended state for this setting is: Enabled. Audit: reads the registry value(s) behind this Defender policy (HKLM\SOFTWARE\Policies\Microsoft\Windows Defender) and prints compliant only when each satisfies the benchmark value. Policy delivered by Intune only appears here once it has been applied to the device.

How it is checked

Audit method: Windows registry

registry

$bad = @(); $v = (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Spynet' -Name 'DisableBlockAtFirstSeen' -ErrorAction SilentlyContinue).'DisableBlockAtFirstSeen'; if (-not ($null -ne $v -and @(0) -contains [int64]$v)) { $bad += 'DisableBlockAtFirstSeen=' + $v }; if ($bad.Count -eq 0) { 'compliant' } else { 'non-compliant: ' + ($bad -join ', ') }

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

To establish the recommended configuration via configuration profiles, set the following Settings Catalog path to Enabled: Administrative Templates\Microsoft Defender Antivirus\MAPS\Configure the 'Block at First Sight' feature

Properties

Operating systems: Any
Tags: intune-defenderintuneregistry
Reference: CIS Microsoft Intune for Microsoft Defender Antivirus Benchmark v1.0.0 - 1.3.2 Ensure 'Configure the 'Block at First Sight' feature' 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 intune-defender