name: Linux Possible Access To Sudoers File
id: 4479539c-71fc-11ec-b2e2-acde48001122
version: 1
date: '2022-01-10'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: This analytic is to detect a possible access or modification of /etc/sudoers
  file. "/etc/sudoers" file controls who can run what command as what users on what
  machine and can also control whether a specific user need a password for particular
  commands.  adversaries and threat actors abuse this file to gain persistence and/or
  privilege escalation during attack on targeted host.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    CommandLine: '*/etc/sudoers*'
    Image|endswith:
    - cat
    - nano*
    - vim*
    - vi*
  condition: selection1
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. If you are using Sysmon, you can use the Add-on for Linux Sysmon from
  Splunkbase.
known_false_positives: administrator or network operator can execute this command.
  Please update the filter macros to remove false positives.
references:
- https://attack.mitre.org/techniques/T1548/003/
- https://web.archive.org/web/20210708035426/https://www.cobaltstrike.com/downloads/csmanual43.pdf
tags:
  analytic_story:
  - Linux Privilege Escalation
  - Linux Persistence Techniques
  asset_type: Endpoint
  confidence: 50
  impact: 50
  message: A commandline $process$ executed on $dest$
  mitre_attack_id:
  - T1548.003
  - T1548
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 25
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1003.008/copy_file_stdoutpipe/sysmon_linux.log
    source: Syslog:Linux-Sysmon/Operational
    sourcetype: sysmon:linux