Service Principal Name SPN Assigned to User Account

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Id	875d0eb1-883a-4191-bd0e-dbfdeb95a464
Rulename	Service Principal Name (SPN) Assigned to User Account
Description	This query identifies whether an Active Directory user object was assigned a service principal name which could indicate that an adversary is preparing for performing Kerberoasting. This query checks for event id 5136, that the Object Class field is “user” and the LDAP Display Name is “servicePrincipalName”. Ref: https://thevivi.net/assets/docs/2019/theVIVI-AD-Security-Workshop_AfricaHackon2019.pdf
Severity	Medium
Tactics	PrivilegeEscalation
Techniques	T1134
Required data connectors	SecurityEvents
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/UserPrincipalNameAssignedToUserAccount.yaml
Version	1.0.4
Arm template	875d0eb1-883a-4191-bd0e-dbfdeb95a464.json

KQL

SecurityEvent
| where EventID == 5136 
| parse EventData with * 'AttributeLDAPDisplayName">' AttributeLDAPDisplayName "<" *
| parse EventData with * 'ObjectClass">' ObjectClass "<" *
| where AttributeLDAPDisplayName == "servicePrincipalName" and  ObjectClass == "user"
| parse EventData with * 'ObjectDN">' ObjectDN "<" *
| parse EventData with * 'AttributeValue">' AttributeValue "<" *
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by Computer, SubjectAccount, ObjectDN, AttributeValue, SubjectUserName, SubjectDomainName, SubjectUserSid
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| project-away DomainIndex

YAML

id: 875d0eb1-883a-4191-bd0e-dbfdeb95a464
tactics:
- PrivilegeEscalation
queryPeriod: 1h
metadata:
  categories:
    domains:
    - Security - Others
    - Identity
  source:
    kind: Community
  support:
    tier: Community
  author:
    name: Vasileios Paschalidis
triggerThreshold: 0
name: Service Principal Name (SPN) Assigned to User Account
query: |
  SecurityEvent
  | where EventID == 5136 
  | parse EventData with * 'AttributeLDAPDisplayName">' AttributeLDAPDisplayName "<" *
  | parse EventData with * 'ObjectClass">' ObjectClass "<" *
  | where AttributeLDAPDisplayName == "servicePrincipalName" and  ObjectClass == "user"
  | parse EventData with * 'ObjectDN">' ObjectDN "<" *
  | parse EventData with * 'AttributeValue">' AttributeValue "<" *
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by Computer, SubjectAccount, ObjectDN, AttributeValue, SubjectUserName, SubjectDomainName, SubjectUserSid
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | project-away DomainIndex  
severity: Medium
triggerOperator: gt
kind: Scheduled
relevantTechniques:
- T1134
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/UserPrincipalNameAssignedToUserAccount.yaml
queryFrequency: 1h
requiredDataConnectors:
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
description: |
  'This query identifies whether an Active Directory user object was assigned a service principal name which could indicate that an adversary is preparing for performing Kerberoasting. 
  This query checks for event id 5136, that the Object Class field is "user" and the LDAP Display Name is "servicePrincipalName".
  Ref: https://thevivi.net/assets/docs/2019/theVIVI-AD-Security-Workshop_AfricaHackon2019.pdf'  
version: 1.0.4
entityMappings:
- fieldMappings:
  - columnName: SubjectAccount
    identifier: FullName
  - columnName: SubjectUserName
    identifier: Name
  - columnName: SubjectDomainName
    identifier: NTDomain
  entityType: Account
- fieldMappings:
  - columnName: SubjectUserSid
    identifier: Sid
  entityType: Account
- fieldMappings:
  - columnName: Computer
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: HostNameDomain
    identifier: NTDomain
  entityType: Host

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/875d0eb1-883a-4191-bd0e-dbfdeb95a464')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/875d0eb1-883a-4191-bd0e-dbfdeb95a464')]",
      "properties": {
        "alertRuleTemplateName": "875d0eb1-883a-4191-bd0e-dbfdeb95a464",
        "customDetails": null,
        "description": "'This query identifies whether an Active Directory user object was assigned a service principal name which could indicate that an adversary is preparing for performing Kerberoasting. \nThis query checks for event id 5136, that the Object Class field is \"user\" and the LDAP Display Name is \"servicePrincipalName\".\nRef: https://thevivi.net/assets/docs/2019/theVIVI-AD-Security-Workshop_AfricaHackon2019.pdf'\n",
        "displayName": "Service Principal Name (SPN) Assigned to User Account",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "SubjectAccount",
                "identifier": "FullName"
              },
              {
                "columnName": "SubjectUserName",
                "identifier": "Name"
              },
              {
                "columnName": "SubjectDomainName",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "SubjectUserSid",
                "identifier": "Sid"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "HostNameDomain",
                "identifier": "NTDomain"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/UserPrincipalNameAssignedToUserAccount.yaml",
        "query": "SecurityEvent\n| where EventID == 5136 \n| parse EventData with * 'AttributeLDAPDisplayName\">' AttributeLDAPDisplayName \"<\" *\n| parse EventData with * 'ObjectClass\">' ObjectClass \"<\" *\n| where AttributeLDAPDisplayName == \"servicePrincipalName\" and  ObjectClass == \"user\"\n| parse EventData with * 'ObjectDN\">' ObjectDN \"<\" *\n| parse EventData with * 'AttributeValue\">' AttributeValue \"<\" *\n| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by Computer, SubjectAccount, ObjectDN, AttributeValue, SubjectUserName, SubjectDomainName, SubjectUserSid\n| extend HostName = tostring(split(Computer, \".\")[0]), DomainIndex = toint(indexof(Computer, '.'))\n| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)\n| project-away DomainIndex\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1134"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}