URL Added to Application from Unknown Domain

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Id	017e095a-94d8-430c-a047-e51a11fb737b
Rulename	URL Added to Application from Unknown Domain
Description	Detects a URL being added to an application where the domain is not one that is associated with the tenant. The query uses domains seen in sign in logs to determine if the domain is associated with the tenant. Applications associated with URLs not controlled by the organization can pose a security risk. Ref: https://learn.microsoft.com/en-gb/entra/architecture/security-operations-applications#application-configuration-changes
Severity	High
Tactics	Persistence PrivilegeEscalation
Techniques	T1078.004
Required data connectors	AzureActiveDirectory
Kind	Scheduled
Query frequency	2h
Query period	2h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/URLAddedtoApplicationfromUnknownDomain.yaml
Version	1.1.1
Arm template	017e095a-94d8-430c-a047-e51a11fb737b.json

KQL

let domains =
  SigninLogs
  | where ResultType == 0
  | extend domain = split(UserPrincipalName, "@")[1]
  | extend domain = tostring(split(UserPrincipalName, "@")[1])
  | summarize by tolower(tostring(domain));
  AuditLogs
  | where Category =~ "ApplicationManagement"
  | where Result =~ "success"
  | where OperationName =~ 'Update Application'
  | mv-expand TargetResources
  | mv-expand TargetResources.modifiedProperties
  | where TargetResources_modifiedProperties.displayName =~ "AppAddress"
  | extend Key = tostring(TargetResources_modifiedProperties.displayName)
  | extend NewValue = TargetResources_modifiedProperties.newValue
  | extend OldValue = TargetResources_modifiedProperties.oldValue
  | where isnotempty(Key) and isnotempty(NewValue)
  | project-reorder Key, NewValue, OldValue
  | extend NewUrls = extract_all('"Address":([^,]*)', tostring(NewValue))
  | extend OldUrls = extract_all('"Address":([^,]*)', tostring(OldValue))
  | extend AddedUrls = set_difference(NewUrls, OldUrls)
  | where array_length(AddedUrls) > 0
  | extend UserAgent = iif(tostring(AdditionalDetails[0].key) == "User-Agent", tostring(AdditionalDetails[0].value), "")
  | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
  | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
  | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
  | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
  | extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)
  | extend InitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName),InitiatingUserPrincipalName, InitiatingAppName))
  | extend AppDisplayName = tostring(TargetResources.displayName)
  | where isnotempty(AddedUrls)
  | mv-expand AddedUrls
  | extend AddedUrls = trim(@'"', tostring(AddedUrls))
  | extend Domain = extract("^(?:https?:\\/\\/)?(?:[^@\\/\\n]+@)?(?:www\\.)?([^:\\/?\\n]+)/", 1, replace_string(tolower(AddedUrls), '"', ""))
  | where isnotempty(Domain)
  | extend Domain = strcat(split(Domain, ".")[-2], ".", split(Domain, ".")[-1])
  | where Domain !in (domains)
  | project-reorder TimeGenerated, AppDisplayName, AddedUrls, InitiatedBy, UserAgent, InitiatingIPAddress
  | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])

YAML

id: 017e095a-94d8-430c-a047-e51a11fb737b
tactics:
- Persistence
- PrivilegeEscalation
queryPeriod: 2h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/URLAddedtoApplicationfromUnknownDomain.yaml
metadata:
  categories:
    domains:
    - Security - Others
  source:
    kind: Community
  support:
    tier: Community
  author:
    name: Microsoft Security Research
triggerThreshold: 0
name: URL Added to Application from Unknown Domain
query: |
  let domains =
    SigninLogs
    | where ResultType == 0
    | extend domain = split(UserPrincipalName, "@")[1]
    | extend domain = tostring(split(UserPrincipalName, "@")[1])
    | summarize by tolower(tostring(domain));
    AuditLogs
    | where Category =~ "ApplicationManagement"
    | where Result =~ "success"
    | where OperationName =~ 'Update Application'
    | mv-expand TargetResources
    | mv-expand TargetResources.modifiedProperties
    | where TargetResources_modifiedProperties.displayName =~ "AppAddress"
    | extend Key = tostring(TargetResources_modifiedProperties.displayName)
    | extend NewValue = TargetResources_modifiedProperties.newValue
    | extend OldValue = TargetResources_modifiedProperties.oldValue
    | where isnotempty(Key) and isnotempty(NewValue)
    | project-reorder Key, NewValue, OldValue
    | extend NewUrls = extract_all('"Address":([^,]*)', tostring(NewValue))
    | extend OldUrls = extract_all('"Address":([^,]*)', tostring(OldValue))
    | extend AddedUrls = set_difference(NewUrls, OldUrls)
    | where array_length(AddedUrls) > 0
    | extend UserAgent = iif(tostring(AdditionalDetails[0].key) == "User-Agent", tostring(AdditionalDetails[0].value), "")
    | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
    | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
    | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
    | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
    | extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)
    | extend InitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName),InitiatingUserPrincipalName, InitiatingAppName))
    | extend AppDisplayName = tostring(TargetResources.displayName)
    | where isnotempty(AddedUrls)
    | mv-expand AddedUrls
    | extend AddedUrls = trim(@'"', tostring(AddedUrls))
    | extend Domain = extract("^(?:https?:\\/\\/)?(?:[^@\\/\\n]+@)?(?:www\\.)?([^:\\/?\\n]+)/", 1, replace_string(tolower(AddedUrls), '"', ""))
    | where isnotempty(Domain)
    | extend Domain = strcat(split(Domain, ".")[-2], ".", split(Domain, ".")[-1])
    | where Domain !in (domains)
    | project-reorder TimeGenerated, AppDisplayName, AddedUrls, InitiatedBy, UserAgent, InitiatingIPAddress
    | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])  
severity: High
triggerOperator: gt
kind: Scheduled
relevantTechniques:
- T1078.004
tags:
- AADSecOpsGuide
queryFrequency: 2h
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - AuditLogs
description: |
  'Detects a URL being added to an application where the domain is not one that is associated with the tenant.
    The query uses domains seen in sign in logs to determine if the domain is associated with the tenant.
    Applications associated with URLs not controlled by the organization can pose a security risk.
    Ref: https://learn.microsoft.com/en-gb/entra/architecture/security-operations-applications#application-configuration-changes'  
version: 1.1.1
entityMappings:
- fieldMappings:
  - columnName: AddedUrls
    identifier: Url
  entityType: URL
- fieldMappings:
  - columnName: InitiatingAppName
    identifier: Name
  - columnName: InitiatingAppServicePrincipalId
    identifier: AadUserId
  entityType: Account
- fieldMappings:
  - columnName: InitiatingUserPrincipalName
    identifier: FullName
  - columnName: InitiatingAccountName
    identifier: Name
  - columnName: InitiatingAccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: InitiatingAadUserId
    identifier: AadUserId
  entityType: Account
- fieldMappings:
  - columnName: InitiatingIPAddress
    identifier: Address
  entityType: IP

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/017e095a-94d8-430c-a047-e51a11fb737b')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/017e095a-94d8-430c-a047-e51a11fb737b')]",
      "properties": {
        "alertRuleTemplateName": "017e095a-94d8-430c-a047-e51a11fb737b",
        "customDetails": null,
        "description": "'Detects a URL being added to an application where the domain is not one that is associated with the tenant.\n  The query uses domains seen in sign in logs to determine if the domain is associated with the tenant.\n  Applications associated with URLs not controlled by the organization can pose a security risk.\n  Ref: https://learn.microsoft.com/en-gb/entra/architecture/security-operations-applications#application-configuration-changes'\n",
        "displayName": "URL Added to Application from Unknown Domain",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "columnName": "AddedUrls",
                "identifier": "Url"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatingAppName",
                "identifier": "Name"
              },
              {
                "columnName": "InitiatingAppServicePrincipalId",
                "identifier": "AadUserId"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatingUserPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "InitiatingAccountName",
                "identifier": "Name"
              },
              {
                "columnName": "InitiatingAccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatingAadUserId",
                "identifier": "AadUserId"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "InitiatingIPAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/URLAddedtoApplicationfromUnknownDomain.yaml",
        "query": "let domains =\n  SigninLogs\n  | where ResultType == 0\n  | extend domain = split(UserPrincipalName, \"@\")[1]\n  | extend domain = tostring(split(UserPrincipalName, \"@\")[1])\n  | summarize by tolower(tostring(domain));\n  AuditLogs\n  | where Category =~ \"ApplicationManagement\"\n  | where Result =~ \"success\"\n  | where OperationName =~ 'Update Application'\n  | mv-expand TargetResources\n  | mv-expand TargetResources.modifiedProperties\n  | where TargetResources_modifiedProperties.displayName =~ \"AppAddress\"\n  | extend Key = tostring(TargetResources_modifiedProperties.displayName)\n  | extend NewValue = TargetResources_modifiedProperties.newValue\n  | extend OldValue = TargetResources_modifiedProperties.oldValue\n  | where isnotempty(Key) and isnotempty(NewValue)\n  | project-reorder Key, NewValue, OldValue\n  | extend NewUrls = extract_all('\"Address\":([^,]*)', tostring(NewValue))\n  | extend OldUrls = extract_all('\"Address\":([^,]*)', tostring(OldValue))\n  | extend AddedUrls = set_difference(NewUrls, OldUrls)\n  | where array_length(AddedUrls) > 0\n  | extend UserAgent = iif(tostring(AdditionalDetails[0].key) == \"User-Agent\", tostring(AdditionalDetails[0].value), \"\")\n  | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)\n  | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)\n  | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)\n  | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)\n  | extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)\n  | extend InitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName),InitiatingUserPrincipalName, InitiatingAppName))\n  | extend AppDisplayName = tostring(TargetResources.displayName)\n  | where isnotempty(AddedUrls)\n  | mv-expand AddedUrls\n  | extend AddedUrls = trim(@'\"', tostring(AddedUrls))\n  | extend Domain = extract(\"^(?:https?:\\\\/\\\\/)?(?:[^@\\\\/\\\\n]+@)?(?:www\\\\.)?([^:\\\\/?\\\\n]+)/\", 1, replace_string(tolower(AddedUrls), '\"', \"\"))\n  | where isnotempty(Domain)\n  | extend Domain = strcat(split(Domain, \".\")[-2], \".\", split(Domain, \".\")[-1])\n  | where Domain !in (domains)\n  | project-reorder TimeGenerated, AppDisplayName, AddedUrls, InitiatedBy, UserAgent, InitiatingIPAddress\n  | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, \"@\")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, \"@\")[1])\n",
        "queryFrequency": "PT2H",
        "queryPeriod": "PT2H",
        "severity": "High",
        "subTechniques": [
          "T1078.004"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence",
          "PrivilegeEscalation"
        ],
        "tags": [
          "AADSecOpsGuide"
        ],
        "techniques": [
          "T1078"
        ],
        "templateVersion": "1.1.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}