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Description

Rubeus is a C# toolset for raw Kerberos interaction and abuses. It is heavily adapted from Benjamin Delpys Kekeo project and Vincent LE TOUXs MakeMeEnterpriseAdmin project. This analytic looks for the use of Rubeus command line arguments utilized in common Kerberos attacks like exporting and importing tickets, forging silver and golden tickets, requesting a TGT or TGS, kerberoasting, password spraying, etc. Red teams and adversaries alike use Rubeus for Kerberos attacks within Active Directory networks. Defenders should be aware that adversaries may customize the source code of Rubeus and modify the command line parameters. This would effectively bypass this analytic.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-02-01
  • Author: Mauricio Velazco, Splunk
  • ID: cca37478-8377-11ec-b59a-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1550 Use Alternate Authentication Material Defense Evasion, Lateral Movement
T1550.003 Pass the Ticket Defense Evasion, Lateral Movement
T1558 Steal or Forge Kerberos Tickets Credential Access
T1558.003 Kerberoasting Credential Access
T1558.004 AS-REP Roasting Credential Access
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process = "*ptt /ticket*" OR Processes.process = "* monitor /interval*" OR Processes.process ="* asktgt* /user:*" OR Processes.process ="* asktgs* /service:*" OR Processes.process ="* golden* /user:*" OR Processes.process ="* silver* /service:*" OR Processes.process ="* kerberoast*" OR Processes.process ="* asreproast*" OR Processes.process = "* renew* /ticket:*" OR Processes.process = "* brute* /password:*" OR Processes.process = "* brute* /passwords:*" OR Processes.process ="* harvest*") by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.parent_process_name 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `rubeus_command_line_parameters_filter`

Macros

The SPL above uses the following Macros:

:information_source: rubeus_command_line_parameters_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_id
  • Processes.parent_process_name

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Although unlikely, legitimate applications may use the same command line parameters as Rubeus. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
36.0 60 60 Rubeus command line parameters were used on $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 1