linux_install_kernel_module_using_modprobe_utility.yml

name: Linux Install Kernel Module Using Modprobe Utility
id: 387b278a-6326-11ec-aa2c-acde48001122
version: 1
date: '2021-12-22'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: This analytic looks for possible installing a linux kernel module using
  modprobe utility function. This event can detect a installation of rootkit or malicious
  kernel module to gain elevated privileges to their malicious code and bypassed detections.
  This Anomaly detection is a good indicator that someone installing kernel module
  in a linux host either admin or adversaries. filter is needed in this scenario
data_source:
- Sysmon for Linux EventID 1
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process_name IN("kmod",
  "sudo") AND Processes.process = *modprobe* by Processes.dest Processes.user Processes.parent_process_name
  Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
  Processes.process_guid | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `linux_install_kernel_module_using_modprobe_utility_filter`'
how_to_implement: The detection is based on data that originates from Endpoint Detection
  and Response (EDR) agents. These agents are designed to provide security-related
  telemetry from the endpoints where the agent is installed. To implement this search,
  you must ingest logs that contain the process GUID, process name, and parent process.
  Additionally, you must ingest complete command-line executions. These logs must
  be processed using the appropriate Splunk Technology Add-ons that are specific to
  the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
  data model. Use the Splunk Common Information Model (CIM) to normalize the field
  names and speed up the data modeling process.
known_false_positives: Administrator or network operator can execute this command.
  Please update the filter macros to remove false positives.
references:
- https://docs.fedoraproject.org/en-US/fedora/rawhide/system-administrators-guide/kernel-module-driver-configuration/Working_with_Kernel_Modules/
- https://security.stackexchange.com/questions/175953/how-to-load-a-malicious-lkm-at-startup
- https://0x00sec.org/t/kernel-rootkits-getting-your-hands-dirty/1485
tags:
  analytic_story:
  - Linux Privilege Escalation
  - Linux Persistence Techniques
  - Linux Rootkit
  asset_type: Endpoint
  confidence: 80
  impact: 80
  message: A commandline $process$ that may install kernel module on $dest$
  mitre_attack_id:
  - T1547.006
  - T1547
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process_name
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_id
  risk_score: 64
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1547.006/loading_linux_kernel_module/sysmon_linux.log
    source: Syslog:Linux-Sysmon/Operational
    sourcetype: sysmon_linux