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

name: Service Principal Name (SPN) Assigned to User Account
relevantTechniques:
- T1134
id: 875d0eb1-883a-4191-bd0e-dbfdeb95a464
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/UserPrincipalNameAssignedToUserAccount.yaml
requiredDataConnectors:
- dataTypes:
  - SecurityEvent
  connectorId: SecurityEvents
version: 1.0.4
severity: Medium
triggerThreshold: 0
metadata:
  source:
    kind: Community
  support:
    tier: Community
  categories:
    domains:
    - Security - Others
    - Identity
  author:
    name: Vasileios Paschalidis
queryPeriod: 1h
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: SubjectAccount
  - identifier: Name
    columnName: SubjectUserName
  - identifier: NTDomain
    columnName: SubjectDomainName
  entityType: Account
- fieldMappings:
  - identifier: Sid
    columnName: SubjectUserSid
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: Computer
  - identifier: HostName
    columnName: HostName
  - identifier: NTDomain
    columnName: HostNameDomain
  entityType: Host
queryFrequency: 1h
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  
tactics:
- PrivilegeEscalation
kind: Scheduled
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'  
triggerOperator: gt

ARM