name: Linux Doas Conf File Creation
id: f6343e86-6e09-11ec-9376-acde48001122
version: 1
date: '2022-01-05'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: This analytic is to detect the creation of doas.conf file in linux host
  platform. This configuration file can be use by doas utility tool to allow or permit
  standard users to perform tasks as root, the same way sudo does. This tool is developed
  as a minimalistic alternative to sudo application. This tool can be abused advesaries,
  attacker or malware to gain elevated privileges to the targeted or compromised host.
  On the other hand this can also be executed by administrator for a certain task
  that needs admin rights. In this case filter is needed.
data_source:
- Sysmon Event ID 11
search:
  selection1:
    TargetFilename: '*/etc/doas.conf'
  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://wiki.gentoo.org/wiki/Doas
- https://www.makeuseof.com/how-to-install-and-use-doas/
tags:
  analytic_story:
  - Linux Privilege Escalation
  - Linux Persistence Techniques
  asset_type: Endpoint
  confidence: 70
  impact: 70
  message: A file $file_name$ is created in $file_path$ 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: 49
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.003/doas/sysmon_linux.log
    source: Syslog:Linux-Sysmon/Operational
    sourcetype: sysmon_linux