What is scanAvgCPULoadFactor in Microsoft Defender Antivirus and when can it get ignored?

-

If you manage Windows Defender AV settings, then you probably would have come across scanAvgCPULoadFactor in same shape or form. In Intune, the setting is called 'Avg CPU Load factor' which is based of the same setting available in the GPO admx template. 'Avg CPU Load factor' is used to specify the maximum percentage of CPU usage for a scan. The acceptable values for this parameter are: integers from 5 through 100, and the value 0, which disables CPU throttling. Windows Defender does not exceed the percentage of CPU usage that you specify. The default value is 50.

While working on an implementation project for Defender for Endpoint, the customer pointed out to me that they were noticing some performance issues after onboarding to Defender for Endpoint and it was soon concluded that the issue could be due to AV scan configuration settings. 

According to Microsoft -

It is not a hard limit but rather a guidance for the scanning engine to not exceed this maximum on average. If ScanOnlyIfIdleEnabled (instructing the product to scan only when the computer is not in use) and DisableCpuThrottleOnIdleScans (instructing the product to disable CPU throttling on idle scans) are both enabled, then the value of ScanAvgCPULoadFactor is ignored.

As it turns out, this was exactly what was happening in my case and it was evidently reporting in the AV settings -


Solution

Since both ScanOnlyIfIdleEnabled & DisableCpuThrottleOnIdleScans are enabled by default, the solution seems straight forward which is to disable them in favor of ScanAvgCPULoadFactor.

However, what is not straight forward is the configuration around it. With Endpoint security profiles in Intune, which are curated and tailored around device security, is usually the preferred choice of managing Defender policies in Intune. The problem is that both ScanOnlyIfIdleEnabled & DisableCpuThrottleOnIdleScans are not available in the default catalog under Microsoft Defender AV profile. So what do you do? Luckily both ScanOnlyIfIdleEnabled & DisableCpuThrottleOnIdleScans are available in Device configuration settings catalog and that is how you can go about configuring them.

2. Browse to Devices –> Configuration
3. Click Create Profile
4. Select Platform as Windows 10 and later
5. Select Profile type as Settings catalog
6. Provide a Name and hit next.
7. Click on Add settings.
8. Search for 'idle' and configure as shown below.



9. Assign to a device or user based group.

Validation

Once applied, the values for ScanOnlyIfIdleEnabled & DisableCpuThrottleOnIdleScans will change to disable them.





Since this wasn't an obvious policy creation in Intune, I thought I will capture the details and share my experience in the hopes of saving others some time.

Thank you for reading this article. Until next time..

Comments

  1. renukaMarch 21, 2024 at 4:35 AM

    Impressive Article. Thanks for sharing.
    Azure DevOps Training Online
    Azure DevOps Online Training
    Azure DevOps Online Training in Hyderabad
    Azure DevOps Course Online
    Microsoft Azure DevOps Online Training
    Azure DevOps Training in Hyderabad
    Azure DevOps Training
    Azure DevOps Training in Ameerpet

    ReplyDelete

Post a Comment

Popular posts from this blog

How to force escrowing of BitLocker recovery keys using Intune

-
Image
Every now and then it so happens that BitLocker recovery keys do not escrow in AAD. The usual culprits are incorrect BitLocker policies and\or the device hardware configuration failing to meet the minimum requirements. The other scenario and something I recently experienced is when everything is setup right and still the recovery key doesn’t escrow in AAD. As I understand, this can happen if the escrow process got interrupted the first time due to network or local devices related issues and the process could not resume. To circumvent this issue, one can simply push a PowerShell script to the devices to force the escrow of the recovery keys to AAD. Here is a script to do so. try{ $BitlockerVol = Get-BitLockerVolume -MountPoint $env:SystemDrive         $KPID=""         foreach($KP in $BitlockerVol.KeyProtector){             if($KP.KeyProtectorType -eq "RecoveryPassword"){                 $KPID=$KP.KeyProtectorId                 break;             }         }        $o
Read more

Intune: Configure Printers for Non-Administrative Users

-
Image
Configuring printers for end users or giving them the ability to do it themselves is a normal requirement for organizations. Now if your users are Administrators, then the configuration can be straight forward, but in case of Non-Administrators there are additional steps required as Non-Administrators will not be able to add a driver in the driver store despite being able to install a printer. In this blog, I will cover the steps that I took to address this requirement using Intune. The setup involves 2 steps -  1. Setup registries. 2. Install the driver and configure the printer Setting up registries – The registries that need to be configured are actually part of a GPO setting – Allow non-administrators to install drivers for these device setup classes It can be found under: Computer Configuration -> Policies -> Administrative Templates -> System -> Driver Installation I used a Powershell script to set the values and wrapped it in a Win32 application. $Path1
Read more

Intune: UAC Elevation Prompt Behavior for Standard Users

-
Image
Implementing and maintaining a good security posture is an integral part of overall IT security governance for most organizations now. While you want to harden the security of infrastructure and give least number of privileges to your end users, sometimes you may need to cut back on the restrictions to ensure a good user experience and an effective IT support process. Recently, I had a requirement where the customer wanted to ease the restriction on the end user devices to make the helpdesk support process more efficient. This involved easing the UAC level access for the Standard users and if you are managing your devices using Intune, then this blog may just help you. Let us see what all is involved and some of the ways that you can use to implement this easily. Policy CSP – LocalPoliciesSecurityOptions LocalPoliciesSecurityOptions has many CSP settings and if you are managing these settings at an individual level, then the CSP that we need to concern ourselves with here is U
Read more