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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.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-01-10
  • Author: Teoderick Contreras, Splunk
  • ID: 4479539c-71fc-11ec-b2e2-acde48001122

ATT&CK

ID Technique Tactic
T1548.003 Sudo and Sudo Caching Privilege Escalation, Defense Evasion
T1548 Abuse Elevation Control Mechanism Privilege Escalation, Defense Evasion 

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name IN("cat", "nano*","vim*", "vi*")  AND Processes.process IN("*/etc/sudoers*") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `linux_possible_access_to_sudoers_file_filter`

Associated Analytic Story

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.

Required field

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_id

Kill Chain Phase

  • Privilege Escalation

Known False Positives

administrator or network operator can execute this command. Please update the filter macros to remove false positives.

RBA

Risk Score Impact Confidence Message
25.0 50 50 A commandline $process$ executed on $dest$

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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