sigma-rules/rules/linux/persistence_kernel_driver_load.toml

[metadata]
creation_date = "2023/10/26"
integration = ["auditd_manager"]
maturity = "production"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"
updated_date = "2024/02/22"

[rule]
author = ["Elastic"]
description = """
Detects the loading of a Linux kernel module through system calls. Threat actors may leverage Linux kernel modules to 
load a rootkit on a system providing them with complete control and the ability to hide from security products. As other
rules monitor for the addition of Linux kernel modules through system utilities or .ko files, this rule covers the gap 
that evasive rootkits leverage by monitoring for kernel module additions on the lowest level through auditd_manager. 
"""
from = "now-9m"
index = ["auditbeat-*", "logs-auditd_manager.auditd-*"]
language = "eql"
license = "Elastic License v2"
name = "Kernel Driver Load"
risk_score = 21
rule_id = "3e12a439-d002-4944-bc42-171c0dcb9b96"
setup = """## Setup
This rule requires the use of the `auditd_manager` integration. `Auditd_manager` is a tool designed to simplify and enhance the management of the audit subsystem in Linux systems. It provides a user-friendly interface and automation capabilities for configuring and monitoring system auditing through the auditd daemon. With `auditd_manager`, administrators can easily define audit rules, track system events, and generate comprehensive audit reports, improving overall security and compliance in the system. The following steps should be executed in order to install and deploy `auditd_manager` on a Linux system. 

```
Kibana -->
Management -->
Integrations -->
Auditd Manager -->
Add Auditd Manager
```

`Auditd_manager` subscribes to the kernel and receives events as they occur without any additional configuration. However, if more advanced configuration is required to detect specific behavior, audit rules can be added to the integration in either the "audit rules" configuration box or the "auditd rule files" box by specifying a file to read the audit rules from. 

For this detection rule to trigger, the following additional audit rules are required to be added to the integration:
```
-a always,exit -F arch=b64 -S finit_module -S init_module -S delete_module -F auid!=-1 -k modules
-a always,exit -F arch=b32 -S finit_module -S init_module -S delete_module -F auid!=-1 -k modules
```

Add the newly installed `auditd manager` to an agent policy, and deploy the agent on a Linux system from which auditd log files are desirable.
"""
severity = "low"
tags = [
        "Data Source: Auditd Manager",
        "Domain: Endpoint",
        "OS: Linux",
        "Use Case: Threat Detection",
        "Tactic: Persistence",
        "Tactic: Defense Evasion"
        ]
timestamp_override = "event.ingested"
type = "eql"
query = '''
driver where host.os.type == "linux" and event.action == "loaded-kernel-module" and
auditd.data.syscall in ("init_module", "finit_module")
'''

[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1547"
name = "Boot or Logon Autostart Execution"
reference = "https://attack.mitre.org/techniques/T1547/"

[[rule.threat.technique.subtechnique]]
id = "T1547.006"
name = "Kernel Modules and Extensions"
reference = "https://attack.mitre.org/techniques/T1547/006/"

[rule.threat.tactic]
id = "TA0003"
name = "Persistence"
reference = "https://attack.mitre.org/tactics/TA0003/"

[[rule.threat]]
framework = "MITRE ATT&CK"

[rule.threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"

[[rule.threat.technique]]
name = "Rootkit"
id = "T1014"
reference = "https://attack.mitre.org/techniques/T1014/"