name: Linux Ruby Privilege Escalation
id: 097b28b5-7004-4d40-a715-7e390501788b
version: 1
date: '2022-08-09'
author: Gowthamaraj Rajendran, Splunk
status: production
type: Anomaly
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.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    CommandLine: '*exec*'
  selection2:
    CommandLine: '*ruby*-e*'
  selection3:
    CommandLine: '*sudo*'
  condition: selection1 and selection2 and selection3
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
  confidence: 50
  impact: 60
  message: An instance of $parent_process_name$ spawning $process_name$ was identified
    on endpoint $dest$
  mitre_attack_id:
  - T1548.003
  - T1548
  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
  risk_score: 30
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548/ruby/sysmon_linux.log
    source: Syslog:Linux-Sysmon/Operational
    sourcetype: sysmon_linux
    update_timestamp: true