Edit

Querying Application Control events centrally using Advanced hunting

A Windows Defender Application Control (WDAC) policy logs events locally in Windows Event Viewer in either enforced or audit mode. While Event Viewer helps to see the impact on a single system, IT Pros want to gauge it across many systems.

In November 2018, we added functionality in Microsoft Defender for Endpoint that makes it easy to view WDAC events centrally from all connected systems.

Advanced hunting in Microsoft Defender for Endpoint allows customers to query data using a rich set of capabilities. WDAC events can be queried with using an ActionType that starts with "AppControl". This capability is supported beginning with Windows version 1607.

Action Types

ActionType Name ETW Source Event ID Description
AppControlCodeIntegrityDriverRevoked 3023 The driver file under validation didn't meet the requirements to pass the application control policy.
AppControlCodeIntegrityImageRevoked 3036 The signed file under validation is signed by a code signing certificate that has been revoked by Microsoft or the certificate issuing authority.
AppControlCodeIntegrityPolicyAudited 3076 This event is the main Windows Defender Application Control block event for audit mode policies. It indicates the file would have been blocked if the WDAC policy was enforced.
AppControlCodeIntegrityPolicyBlocked 3077 This event is the main Windows Defender Application Control block event for enforced policies. It indicates the file didn't pass your WDAC policy and was blocked.
AppControlExecutableAudited 8003 Applied only when the Audit only enforcement mode is enabled. Specifies the .exe or .dll file would be blocked if the Enforce rules enforcement mode were enabled.
AppControlExecutableBlocked 8004 The .exe or .dll file can't run.
AppControlPackagedAppAudited 8021 Applied only when the Audit only enforcement mode is enabled. Specifies the packaged app would be blocked if the Enforce rules enforcement mode were enabled.
AppControlPackagedAppBlocked 8022 The packaged app was blocked by the policy.
AppControlScriptAudited 8006 Applied only when the Audit only enforcement mode is enabled. Specifies the script or .msi file would be blocked if the Enforce rules enforcement mode were enabled.
AppControlScriptBlocked 8007 Access to file name is restricted by the administrator. Applied only when the Enforce rules enforcement mode is set either directly or indirectly through Group Policy inheritance. The script or .msi file can't run.
AppControlCIScriptAudited 8028 Audit script/MSI file generated by Windows LockDown Policy (WLDP) being called by the script hosts themselves.
AppControlCIScriptBlocked 8029 Block script/MSI file generated by Windows LockDown Policy (WLDP) being called by the script hosts themselves.
AppControlCodeIntegrityOriginAllowed 3090 File was allowed due to good reputation (ISG) or installation source (managed installer).
AppControlCodeIntegrityOriginAudited 3091 Reputation (ISG) and installation source (managed installer) information for an audited file.
AppControlCodeIntegrityOriginBlocked 3092 Reputation (ISG) and installation source (managed installer) information for a blocked file.
AppControlCodeIntegrityPolicyLoaded 3099 Indicates a policy has been successfully loaded.
AppControlCodeIntegritySigningInformation 3089 Signing information event correlated with either a 3076 or 3077 event. One 3089 event is generated for each signature of a file.
AppControlPolicyApplied 8001 Indicates the AppLocker policy was successfully applied to the computer.

Learn more about the Understanding Application Control event IDs (Windows)

Example Advanced Hunting Application Control Queries

Query Example 1: Query the application control action types summarized by type for past seven days

Here's a simple example query that shows all the Windows Defender Application Control events generated in the last seven days from machines being monitored by Microsoft Defender for Endpoint:

DeviceEvents
| where Timestamp > ago(7d) and
ActionType startswith "AppControl"
| summarize Machines=dcount(DeviceName) by ActionType
| order by Machines desc

The query results can be used for several important functions related to managing Windows Defender Application Control including:

  • Assessing the impact of deploying policies in audit mode Since applications still run in audit mode, it's an ideal way to see the impact and correctness of the rules included in the policy. Integrating the generated events with Advanced Hunting makes it much easier to have broad deployments of audit mode policies and see how the included rules would influence those systems in real world usage. This audit mode data will help streamline the transition to using policies in enforced mode.
  • Monitoring blocks from policies in enforced mode Policies deployed in enforced mode may block executables or scripts that fail to meet any of the included allow rules. Legitimate new applications and updates or potentially unwanted or malicious software could be blocked. In either case, the Advanced hunting queries report the blocks for further investigation.

Query Example #2: Query to determine audit blocks in the past seven days

DeviceEvents 
| where ActionType startswith "AppControlExecutableAudited"
| where Timestamp > ago(7d)
|project DeviceId,                               // the device ID where the audit block happened
FileName,                                        // The audit blocked app's filename
FolderPath,                                      // The audit blocked app's system path without the FileName
InitiatingProcessFileName,                       // The file name of the parent process loading the executable
InitiatingProcessVersionInfoCompanyName,         // The company name of the parent process loading the executable
InitiatingProcessVersionInfoOriginalFileName,    // The original file name of the parent process loading the executable
InitiatingProcessVersionInfoProductName,         // The product name of the parent process loading the executable
InitiatingProcessSHA256,                         // The SHA256 flat hash of the parent process loading the executable
Timestamp,                                       // The event creation timestamp
ReportId,                                        // The report ID - randomly generated by MDE AH
InitiatingProcessVersionInfoProductVersion,      // The product version of the parent process loading the executable
InitiatingProcessVersionInfoFileDescription,     // The file description of the parent process loading the executable
AdditionalFields                                 // Additional fields contains FQBN for signed binaries.  These contain the CN of the leaf certificate, product name, original filename and version of the audited binary