Detection rules › Splunk

Windows Computer Account Created by Computer Account

Author
Michael Haag, Splunk
Source
upstream

The following analytic identifies a computer account creating a new computer account with a specific Service Principal Name (SPN) "RestrictedKrbHost". This detection leverages Windows Security Event Logs, specifically EventCode 4741, to identify such activities. This behavior is significant as it may indicate an attempt to establish unauthorized Kerberos authentication channels, potentially leading to lateral movement or privilege escalation. If confirmed malicious, this activity could allow an attacker to impersonate services, access sensitive information, or maintain persistence within the network.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1558 Steal or Forge Kerberos Tickets

Event coverage

ProviderEvent IDTitle
Security-Auditing4741A computer account was created.

Stages and Predicates

Stage 1: search

search EventCode=4741 ServicePrincipalNames="*RestrictedKrbHost*" SubjectDomainName!="NT AUTHORITY" user_type="computer"

Stage 2: stats

stats BY dest, subject, action, src_user, user, user_type, SubjectUserName, SubjectDomainName

Stage 3: search

search

Stage 4: search

search

Stage 5: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 4741 corpus 2 (splunk 2)
ServicePrincipalNameseq
  • *RestrictedKrbHost*
SubjectDomainNamene
  • "NT AUTHORITY"
user_typeeq
  • computer