name: Linux Ruby Privilege Escalation
id: 097b28b5-7004-4d40-a715-7e390501788b
version: 1
date: '2022-08-09'
author: Gowthamaraj Rajendran, Splunk
type: Anomaly
datamodel:
- Endpoint
description: Ruby is one of the most used and easy to use programming languages. 
  Ruby is an open-source, object-oriented interpreter that can be installed on a Linux system.
  If sudo right is given to ruby application for the user, then the user can run system commands as root and possibly get a root shell.
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process="*ruby*-e*" AND Processes.process="*exec*" AND Processes.process="*sudo*" by Processes.dest Processes.user Processes.parent_process_name
  Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
  Processes.process_guid | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `linux_ruby_privilege_escalation_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting
  logs with the process name, parent process, and command-line executions from your
  endpoints into the Endpoint datamodel. If you are using Sysmon, you can use the Add-on for Linux Sysmon from
  Splunkbase.
known_false_positives: False positives are present based on automated tooling or system administrative usage. Filter as needed.
references:
- https://gtfobins.github.io/gtfobins/ruby/
tags:
  analytic_story:
  - Linux Privilege Escalation
  - Linux Living Off The Land
  asset_type: Endpoint
  cis20:
  - CIS 3
  - CIS 5
  - CIS 16
  confidence: 50
  context:
  - Source:Endpoint
  - Stage:Privilege Escalation
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548/ruby/sysmon_linux.log
  impact: 60
  kill_chain_phases:
  - Exploitation
  message: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$
  mitre_attack_id:
  - T1548.003
  - T1548
  nist:
  - DE.CM
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: parent_process_name
    type: Process
    role:
    - Parent Process
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process_name
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_id
  risk_score: 30
  security_domain: endpoint