Firefox with NoScript enabled hangs with MDE together

[bruncsak]

Firefox with NoScript enabled hangs on a windows system if Microsoft Defender for Endpoint is running.

MDE console messages:

OS: Windows 10 Enterprise 22H2, build: 19045.5131
Firefox: 133.0.3 (64-bit)
NoScript: 11.5.2
MDE configuration detailes:

PS L:\> Get-MpComputerStatus


AMEngineVersion                  : 1.1.24090.11
AMProductVersion                 : 4.18.24090.11
AMRunningMode                    : Passive Mode
AMServiceEnabled                 : True
AMServiceVersion                 : 4.18.24090.11
AntispywareEnabled               : True
AntispywareSignatureAge          : 1
AntispywareSignatureLastUpdated  : 12/11/2024 1:57:33 PM
AntispywareSignatureVersion      : 1.421.739.0
AntivirusEnabled                 : True
AntivirusSignatureAge            : 1
AntivirusSignatureLastUpdated    : 12/11/2024 1:57:30 PM
AntivirusSignatureVersion        : 1.421.739.0
BehaviorMonitorEnabled           : True
ComputerID                       : <redacted>
ComputerState                    : 0
DefenderSignaturesOutOfDate      : False
DeviceControlDefaultEnforcement  :
DeviceControlPoliciesLastUpdated : 1/1/1601 1:00:00 AM
DeviceControlState               : Disabled
FullScanAge                      : 4294967295
FullScanEndTime                  :
FullScanOverdue                  : False
FullScanRequired                 : False
FullScanSignatureVersion         :
FullScanStartTime                :
InitializationProgress           : ServiceStartedSuccessfully
IoavProtectionEnabled            : False
IsTamperProtected                : True
IsVirtualMachine                 : False
LastFullScanSource               : 0
LastQuickScanSource              : 2
NISEnabled                       : False
NISEngineVersion                 : 1.1.24090.11
NISSignatureAge                  : 65535
NISSignatureLastUpdated          :
NISSignatureVersion              :
OnAccessProtectionEnabled        : False
ProductStatus                    : 524288
QuickScanAge                     : 1
QuickScanEndTime                 : 12/11/2024 6:43:01 AM
QuickScanOverdue                 : False
QuickScanSignatureVersion        : 1.421.725.0
QuickScanStartTime               : 12/11/2024 6:39:40 AM
RealTimeProtectionEnabled        : True
RealTimeScanDirection            : 0
RebootRequired                   : False
SmartAppControlExpiration        :
SmartAppControlState             : Off
TamperProtectionSource           : ATP
TDTCapable                       : N/A
TDTMode                          : N/A
TDTSiloType                      : N/A
TDTStatus                        : N/A
TDTTelemetry                     : N/A
TroubleShootingDailyMaxQuota     :
TroubleShootingDailyQuotaLeft    :
TroubleShootingEndTime           :
TroubleShootingExpirationLeft    :
TroubleShootingMode              :
TroubleShootingModeSource        :
TroubleShootingQuotaResetTime    :
TroubleShootingStartTime         :
PSComputerName                   :

[hackademix]

Thank you for your report.

1. Does this happen on a clean profile with just NoScript installed and default settings?
2. If not, could you please share your [i]NoScript Options>Export[/i] file?
3. Does MDE install a Firefox extension of its own?

[bruncsak]

Thank you for the questions.

I exported the options, then made a reset options.
When I reenable the extension, the same "hang" behaviour of the Firefox occurs.
So it is enough to have the default settings to reproduce the issue.

No, there is no extension installed by MDE.
In fact, on my Firefox the NoScript is the only extension installed.

1. EDIT: Sorry I did not do with clean profile, I do not know how to do that (without loosing the current one). I have about 100 tabs open.
2. EDIT: I had CrowdStrike Falcon sensor installed in parallel to MDE. However, the same probem persists after uninstalling CrowdStrike.
3. EDIT: with clean profile (of couse new installation of NoScript extension into it) I had no problem using MDE and NoScript together. I have to investigate further what is going on within my existing, non-vanilla profile.
4. EDIT: I cannot reproduce the problem any more. The following MDE settings changed on the meantime, but that may not be related:

AMRunningMode                    : Normal
IoavProtectionEnabled            : True
NISEnabled                       : True
OnAccessProtectionEnabled        : True