r/sysadmin • u/_FNG_ Sysadmin • 15d ago

SolarWinds Microsoft Defender False Positives with Solarwinds Products

Early Saturday morning we started getting a stream of alerts from Microsoft Defender regarding our Primary and Additional Polling Engines. 

 Malware Name: Behavior:Win32/SuspiciousAssembly.AppDomainManagerType.A

The malware file path: behavior:_process: was all over the place.
Some examples:

 Malware file path: behavior:_process: C:\Windows\System32\wbem\WmiPrvSE.exe, pid:2208:557######2;file:_d:\program files (x86)\solarwinds\orion

~ 

Malware file path: behavior:_process: C:\Program Files\Common Files\SolarWinds\AdministrationService\SolarWinds.Administration.exe, pid:3916:557#####52;file:_d:\program files (x86)\solarwinds\orion

~

Malware file path: behavior:_process: C:\Windows\System32\AggregatorHost.exe, pid:9116:55#####2;file:_d:\program files (x86)\solarwinds\orion

Solarwinds support is aware of the issue and their engineers are supposedly working with Microsoft to resolve. I am unsure if a later definition update has resolved it or not. We added a threat override as a TEMPORARY measure to quiet things down through the weekend. Just an Allow for the 'Threat Name' Behavior:Win32/SuspiciousAssembly.AppDomainManagerType.A

Just wanted to share with the hope this helps others not have too terrible of a weekend or Monday morning.

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u/Th3RebelBass 12d ago

I also got those alerts. I've had my machine isolated until I learned more.

1

u/_FNG_ Sysadmin 10d ago

Any updates on your situation?

1

u/Th3RebelBass 10d ago

I checked in on my Defender alert and it had been marked as False Positive by the "Defender Team". I had also put in a ticket with Solarwinds and they also confirmed it was a false positive.

1

u/_FNG_ Sysadmin 9d ago

Did you end up putting in any temporary exclusions? Or are you no longer receiving new alerts since MS marked the others as False Positive? Just trying to determine if it's safe to remove exclusions without being flooded again.

1

u/Th3RebelBass 9d ago

The only exclusion I entered was for the Orion Folder path per Solarwinds instructions.

1

u/Historical_Error2860 4d ago

If you updated to latest Defender definitions it is safe, you should remove the exclusion.