Service Principal Name (SPN) Assigned to User Account

id: 875d0eb1-883a-4191-bd0e-dbfdeb95a464
name: 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
requiredDataConnectors:
  - connectorId: SecurityEvents
    dataTypes:
      - SecurityEvent
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - PrivilegeEscalation
relevantTechniques:
  - T1134
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
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: SubjectAccount
      - identifier: Name
        columnName: SubjectUserName
      - identifier: NTDomain
        columnName: SubjectDomainName
  - entityType: Account
    fieldMappings:
      - identifier: Sid
        columnName: SubjectUserSid
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: Computer
      - identifier: HostName
        columnName: HostName
      - identifier: NTDomain
        columnName: HostNameDomain
version: 1.0.4
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Vasileios Paschalidis
    support:
        tier: Community
    categories:
        domains: [ "Security - Others", "Identity" ]