name: Linux Sudoers Tmp File Creation
id: be254a5c-63e7-11ec-89da-acde48001122
version: 1
date: '2021-12-23'
author: Teoderick Contreras, Splunk
type: Anomaly
datamodel:
- Endpoint
description: This analytic is to looks for file creation of sudoers.tmp file cause
  by editing /etc/sudoers using visudo or editor in linux platform. This technique
  may abuse by adversaries, malware author and red teamers to gain elevated privilege
  to targeted or compromised host. /etc/sudoers file controls who can run what commands
  as what users on what machines and can also control special things such as whether
  you need a password for particular commands. The file is composed of aliases (basically
  variables) and user specifications (which control who can run what).
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_path IN ("*sudoers.tmp*")
  by Filesystem.dest Filesystem.file_name Filesystem.process_guid Filesystem.file_path
  | `drop_dm_object_name(Filesystem)` | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)`
  | `linux_sudoers_tmp_file_creation_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. 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://forum.ubuntuusers.de/topic/sudo-visudo-gibt-etc-sudoers-tmp/
tags:
  analytic_story:
  - Linux Privilege Escalation
  - Linux Persistence Techniques
  automated_detection_testing: passed
  cis20:
  - CIS 3
  - CIS 5
  - CIS 16
  confidence: 90
  context:
  - Source:Endpoint
  - Stage:Privilege Escalation
  - Stage:Persistence
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.003/sudoers_temp/sysmon_linux.log
  impact: 80
  kill_chain_phases:
  - Exploitation
  message: A file $file_name$ is created in $file_path$ on $dest$
  mitre_attack_id:
  - T1548.003
  - T1548
  nist:
  - DE.CM
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Filesystem.dest
  - Filesystem.file_create_time
  - Filesystem.file_name
  - Filesystem.process_guid
  - Filesystem.file_path
  risk_score: 72
  security_domain: endpoint
  asset_type: Endpoint