Detection rules › Splunk

Kerberoasting spn request with RC4 encryption

Author
Jose Hernandez, Patrick Bareiss, Mauricio Velazco, Dean Luxton, Splunk
Source
upstream

The following analytic detects potential Kerberoasting attacks by identifying Kerberos service ticket requests with RC4 encryption through Event ID 4769. It leverages specific Ticket_Options values commonly used by Kerberoasting tools. This activity is significant as Kerberoasting allows attackers to request service tickets for domain accounts, typically service accounts, and crack them offline to gain privileged access. If confirmed malicious, this could lead to unauthorized access, privilege escalation, and further compromise of the Active Directory environment.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1558.003 Steal or Forge Kerberos Tickets: Kerberoasting

Event coverage

ProviderEvent IDTitle
Security-Auditing4769A Kerberos service ticket was requested.

Stages and Predicates

Stage 1: search

search (TicketOptions=0x40800000 OR TicketOptions=0x40810000 OR TicketOptions=0x40810010) EventCode=4769 ServiceName!="*$" TicketEncryptionType=0x17

Stage 2: stats

stats BY Computer, user, service_id, service, TicketEncryptionType, TicketOptions

Stage 3: rename

rename

Stage 4: search

search

Stage 5: search

search

Stage 6: 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
  • 4769 corpus 6 (splunk 6)
ServiceNamene
  • "*$" corpus 2 (splunk 2)
TicketEncryptionTypeeq
  • 0x17 corpus 7 (splunk 4, sigma 3)
TicketOptionseq
  • 0x40800000 corpus 2 (splunk 2)
  • 0x40810000 corpus 3 (splunk 2, sigma 1)
  • 0x40810010 corpus 2 (splunk 2)

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.