[Entra ID] Application Assigned Administrator Permissions Immediately After Obtaining Role Management Permissions

Requête originale, sans modification.

let query_frequency = 1h;
let query_period = 2h;
AuditLogs
| where TimeGenerated > ago(query_period)
| where Category =~ "ApplicationManagement" and LoggedByService =~ "Core Directory"
| where OperationName =~ "Add app role assignment to service principal"
| mv-expand TargetResource = TargetResources
| mv-expand modifiedProperty = TargetResource["modifiedProperties"]
| where tostring(modifiedProperty["displayName"]) == "AppRole.Value"
| extend PermissionGrant = tostring(modifiedProperty["newValue"])
| where PermissionGrant has "RoleManagement.ReadWrite.Directory"
| mv-apply modifiedProperty = TargetResource["modifiedProperties"] on (
    summarize modifiedProperties = make_bag(
                                   bag_pack(
    tostring(modifiedProperty["displayName"]),
    bag_pack(
    "oldValue",
    trim(@'[\"\s]+', tostring(modifiedProperty["oldValue"])),
    "newValue",
    trim(@'[\"\s]+', tostring(modifiedProperty["newValue"]))
)
),
                                   100
                               )
    )
| project
    PermissionGrant_TimeGenerated = TimeGenerated,
    PermissionGrant_OperationName = OperationName,
    PermissionGrant_Result = Result,
    PermissionGrant,
    AppDisplayName = tostring(modifiedProperties["ServicePrincipal.DisplayName"]["newValue"]),
    AppServicePrincipalId = tostring(modifiedProperties["ServicePrincipal.ObjectID"]["newValue"]),
    PermissionGrant_InitiatedBy = InitiatedBy,
    PermissionGrant_TargetResources = TargetResources,
    PermissionGrant_AdditionalDetails = AdditionalDetails,
    PermissionGrant_CorrelationId = CorrelationId
| join kind=inner (
    AuditLogs
    | where TimeGenerated > ago(query_frequency)
    | where Category =~ "RoleManagement"
        and LoggedByService =~ "Core Directory"
        and AADOperationType =~ "Assign"
    | where isnotempty(InitiatedBy["app"])
    | mv-expand TargetResource = TargetResources
    | mv-expand modifiedProperty = TargetResource["modifiedProperties"]
    | where tostring(modifiedProperty["displayName"]) in ("Role.DisplayName", "RoleDefinition.DisplayName")
    | extend RoleAssignment = tostring(modifiedProperty["newValue"])
    | where RoleAssignment contains "Admin"
    | project
        RoleAssignment_TimeGenerated = TimeGenerated,
        RoleAssignment_OperationName = OperationName,
        RoleAssignment_Result = Result,
        RoleAssignment,
        TargetType = tostring(TargetResources[0]["type"]),
        Target = iff(isnotempty(TargetResources[0]["displayName"]), tostring(TargetResources[0]["displayName"]), tolower(TargetResources[0]["userPrincipalName"])),
        TargetId = tostring(TargetResources[0]["id"]),
        RoleAssignment_InitiatedBy = InitiatedBy,
        RoleAssignment_TargetResources = TargetResources,
        RoleAssignment_AdditionalDetails = AdditionalDetails,
        RoleAssignment_CorrelationId = CorrelationId,
        AppServicePrincipalId = tostring(InitiatedBy["app"]["servicePrincipalId"])
    )
    on AppServicePrincipalId
| where PermissionGrant_TimeGenerated < RoleAssignment_TimeGenerated
| extend
    TargetName = tostring(split(Target, "@")[0]),
    TargetUPNSuffix = tostring(split(Target, "@")[1])
| project
        Alert_Category_en = "Entra ID",
    Alert_SubCategory_en = "Anomaly Identity Privilege Modification",
    Alert_Name_en = "Application Assigned Administrator Permissions Immediately After Obtaining Role Management Permissions",
    Alert_Description_en = strcat(
                           "At Taiwan time",
                           format_datetime(datetime_utc_to_local(RoleAssignment_TimeGenerated, "Asia/Taipei"), "yyyy-MM-dd HH:mm:ss"),
                           ". ",
                           "EntraID:",
                           "",
                           ". ",
                           "detected initiator: ",
                           tostring(PermissionGrant_InitiatedBy.user.userPrincipalName),
                           " granted application: ",
                           AppDisplayName,
                           " permission: ",
                           PermissionGrant,
                           "afterward, the application immediately assigned a role to target: ",
                           Target,
                           "role assignment: ",
                           RoleAssignment
                       ),
    Alert_TriageStep_en = strcat(
                          "1. Confirm initiator: ",
                          tostring(PermissionGrant_InitiatedBy.user.userPrincipalName),
                          "IP:",
                          tostring(PermissionGrant_InitiatedBy.ipAddress),
                          ", and review the authorized application: ",
                          AppDisplayName,
                          ", obtained permission: ",
                          PermissionGrant,
                          ", to determine whether it is expected behavior/automation. ",
                          "2. Review application: ",
                          AppDisplayName,
                          " for target: ",
                          Target,
                          " role assignment content: ",
                          RoleAssignment,
                          ", to determine whether it is expected behavior/automation. "
                      ),
    Alert_Containment_en = strcat(
                           "1. If determined to be unauthorized behavior, immediately disable initiator: ",
                           tostring(PermissionGrant_InitiatedBy.user.userPrincipalName),
                           " and application: ",
                           AppDisplayName,
                           ", and revoke its Directory/RoleManagement-related permissions. ",
                           "2. Immediately revert/remove the improper administrator role assignment: ",
                           Target,
                           ", and review whether other role/group/application assignments were changed."
                       ),
    Alert_Remediation_en =
    "1. Strengthen Conditional Access and account governance: enforce MFA/managed device and named location restrictions for administrator accounts, and block abnormal IPs. "
    "2. Implement least privilege and PIM: use Just-In-Time (JIT) activation with approval for administrator roles to reduce the risk of immediate abuse after account compromise. "
    "3. Strengthen detection and automation: establish automated response SOAR (notification/revoke authorization/disable application/revert role/block source).",
            Alert_Time_TW = datetime_utc_to_local(RoleAssignment_TimeGenerated, "Asia/Taipei"),
    Alert_Time_UTC0 = RoleAssignment_TimeGenerated,
    Event_Action = RoleAssignment_OperationName,
    Event_Status = RoleAssignment_Result,
    Event_Description = strcat("initiator: ", tostring(PermissionGrant_InitiatedBy.user.userPrincipalName), " to application: ", AppDisplayName, ", ", PermissionGrant_OperationName, ". Subsequently, application: ", AppDisplayName, " for target ", Target, ", ", RoleAssignment_OperationName),
    Source_Identity_FullName = AppDisplayName,
    Source_Identity_ID = AppServicePrincipalId,
    Source_Identity_Type = "Service",
    Target_Identity_FullName = Target,
    Target_Identity_ID = TargetId,
    Target_Identity_Name = TargetName,
    Target_Identity_Type = iff(TargetType has "User", "User", "Service"),
    Target_Resource_ID = "",
    Target_Resource_Name = "Microsoft Entra ID",
    Target_Resource_Type = "Microsoft Entra ID"