splApache-2.0from splunk/security_content
Unusual Number of Computer Service Tickets Requested
The following analytic identifies an unusual number of computer service ticket requests from a single source, leveraging Event ID 4769, "A Kerberos service ticket was requested." It uses statistical analysis, including standard deviation and the 3-sigma rule, to detect anomalies in service ticket requests. This activity is significant as it may indicate malicious behavior such as lateral movement, malware staging, or reconnaissance. If confirmed malicious, an attacker could gain unauthorized access to multiple endpoints, facilitating further compromise and potential data exfiltration.
Quality
51
FP risk
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Rule sourcedetections/endpoint/unusual_number_of_computer_service_tickets_requested.yml
`wineventlog_security` EventCode=4769 Service_Name="*$" Account_Name!="*$*"
| bucket span=2m _time
| stats dc(Service_Name) AS unique_targets values(Service_Name) as host_targets
BY _time, Client_Address, Account_Name
| eventstats avg(unique_targets) as comp_avg , stdev(unique_targets) as comp_std
BY Client_Address, Account_Name
| eval upperBound=(comp_avg+comp_std*3)
| eval isOutlier=if(unique_targets >10 and unique_targets >= upperBound, 1, 0)
| `unusual_number_of_computer_service_tickets_requested_filter`