Defender AV - Active/Passive Mode - Advanced Hunting

[amueller-tf]

While researching how to verify if Defender AV is in active or passive mode I found an Advanced Hunting query that searches "DeviceTvmSecureConfigurationAssessment" and then filters "ConfigurationId" by "scid-2010" as the "Context" column contains the status of Defender AV.

So far, I discovered that:

• "0" = Defender AV is active,
• "1" = Defender AV is passive,
• "4" = Defender AV is in "EDR Block Mode"

I am not sure what "Unknown" in the "Context" column means though. Does it mean that Defender AV is not installed, or that it was manually disabled (via registry keys, GPO, ...) or that it running but not reporting?

[#2]

Can you please share the query

[#3]

@peter_georgeCertainly. I found the script at https://www.reddit.com/r/DefenderATP/comments/lfd5zy/comment/gmynulv/?utm_source=share&utm_medium=we.... Here it is:

let avmodetable = DeviceTvmSecureConfigurationAssessment
| where ConfigurationId == "scid-2010" and isnotnull(Context)
| extend avdata=parsejson(Context)
| extend AVMode = iif(tostring(avdata[0][0]) == '0', 'Active' , iif(tostring(avdata[0][0]) == '1', 'Passive' ,iif(tostring(avdata[0][0]) == '4', 'EDR Blocked' ,'Unknown')))
| project DeviceId, AVMode;
DeviceTvmSecureConfigurationAssessment
| where ConfigurationId == "scid-2011" and isnotnull(Context)
| extend avdata=parsejson(Context)
| extend AVSigVersion = tostring(avdata[0][0])
| extend AVEngineVersion = tostring(avdata[0][1])
| extend AVSigLastUpdateTime = tostring(avdata[0][2])
| project DeviceId, DeviceName, OSPlatform, AVSigVersion, AVEngineVersion, AVSigLastUpdateTime, IsCompliant, IsApplicable
| join avmodetable on DeviceId
| project-away DeviceId1

[#4]

I noticed the server that shows unknown is running Windows Server 2012 R2
The query looks for Microsoft Defender AV data, which is not integrated in 2012 R2,
so I am going to assume this query is not able to get the info in question on Windows 2012 R2 machines since Defender does not exist.
(The link on reddit also does not mention any other platform than Windows 10 and Server 2019)

[#5]

@Jonhed 

I just ran this script in a production environment and there are around 500 Windows 10 devices with AVMode "Unknown" which I assume means that Defender AV is completely disabled.

And this is a screenshot of when I run the script in my demo environment (with the "new" MDE agent installed on it ... https://techcommunity.microsoft.com/t5/microsoft-defender-for-endpoint/defending-windows-server-2012.... Defender AV AVMode shows up as "Active" on Windows Server 2012 R2.

[#6]

@amueller-tf 

Judging by the new screenshots, I agree that it looks like the unknown status means that AV is completely disabled (service not running or is not installed).

[#7]

AVmode will also show Unknown if SCEP is installed, like I have on a few VERY old machines.

[#8]

Hi, how i can add the last user logged at result?

[#9]

You can add a join to the query above to the one below
DeviceLogonEvents
| where ActionType == "LogonSuccess"
| summarize arg_max(TimeGenerated,*) by DeviceId
| project TimeGenerated, DeviceId, AccountName, AccountDomain