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

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

ARM