From 1071b12f00decf9233a4881dae4a739e435afe06 Mon Sep 17 00:00:00 2001
From: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
Date: Thu, 7 Dec 2023 20:59:07 +0100
Subject: [PATCH] [New Rule] Suspicious Kworker UID Elevation (#3238)

* [New Rule] Suspicious Kworker UID Elevation

* Update privilege_escalation_kworker_uid_elevation.toml

---------

Co-authored-by: Colson Wilhoit <48036388+DefSecSentinel@users.noreply.github.com>
---
 ...lege_escalation_kworker_uid_elevation.toml | 99 +++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 rules/linux/privilege_escalation_kworker_uid_elevation.toml

diff --git a/rules/linux/privilege_escalation_kworker_uid_elevation.toml b/rules/linux/privilege_escalation_kworker_uid_elevation.toml
new file mode 100644
index 000000000..4f9b18945
--- /dev/null
+++ b/rules/linux/privilege_escalation_kworker_uid_elevation.toml
@@ -0,0 +1,99 @@
+[metadata]
+creation_date = "2023/10/26"
+integration = ["endpoint"]
+maturity = "production"
+min_stack_comments = "New fields added: required_fields, related_integrations, setup"
+min_stack_version = "8.3.0"
+updated_date = "2023/10/26"
+
+[rule]
+author = ["Elastic"]
+description = """
+Monitors for the elevation of regular user permissions to root permissions through the kworker process. kworker, or
+kernel worker, processes are part of the kernel's workqueue mechanism. They are responsible for executing work that has
+been scheduled to be done in kernel space, which might include tasks like handling interrupts, background activities,
+and other kernel-related tasks. Attackers may attempt to evade detection by masquerading as a kernel worker process, and
+hijack the execution flow by hooking certain functions/syscalls through a rootkit in order to provide easy access to
+root via a special modified command.
+"""
+from = "now-9m"
+index = ["logs-endpoint.events.*"]
+language = "eql"
+license = "Elastic License v2"
+name = "Suspicious Kworker UID Elevation"
+risk_score = 47
+rule_id = "7dfaaa17-425c-4fe7-bd36-83705fde7c2b"
+setup = """
+
+This rule requires data coming in from Elastic Defend.
+
+### Elastic Defend Integration Setup
+Elastic Defend is integrated into the Elastic Agent using Fleet. Upon configuration, the integration allows
+the Elastic Agent to monitor events on your host and send data to the Elastic Security app.
+
+#### Prerequisite Requirements:
+- Fleet is required for Elastic Defend.
+- To configure Fleet Server refer to the [documentation](https://www.elastic.co/guide/en/fleet/current/fleet-server.html).
+
+#### The following steps should be executed in order to add the Elastic Defend integration on a Linux System:
+- Go to the Kibana home page and click Add integrations.
+- In the query bar, search for Elastic Defend and select the integration to see more details about it.
+- Click Add Elastic Defend.
+- Configure the integration name and optionally add a description.
+- Select the type of environment you want to protect, either Traditional Endpoints or Cloud Workloads.
+- Select a configuration preset. Each preset comes with different default settings for Elastic Agent, you can further customize these later by configuring the Elastic Defend integration policy. [Helper guide](https://www.elastic.co/guide/en/security/current/configure-endpoint-integration-policy.html).
+- We suggest to select "Complete EDR (Endpoint Detection and Response)" as a configuration setting, that provides "All events; all preventions"
+- Enter a name for the agent policy in New agent policy name. If other agent policies already exist, you can click the Existing hosts tab and select an existing policy instead.
+For more details on Elastic Agent configuration settings, refer to the [helper guide](https://www.elastic.co/guide/en/fleet/8.10/agent-policy.html).
+- Click Save and Continue.
+- To complete the integration, select Add Elastic Agent to your hosts and continue to the next section to install the Elastic Agent on your hosts.
+For more details on Elastic Defend refer to the [helper guide](https://www.elastic.co/guide/en/security/current/install-endpoint.html).
+
+"""
+severity = "medium"
+tags = [
+        "Domain: Endpoint",
+        "OS: Linux",
+        "Use Case: Threat Detection",
+        "Tactic: Privilege Escalation",
+        "Tactic: Defense Evasion",
+        "Data Source: Elastic Defend"
+        ]
+timestamp_override = "event.ingested"
+type = "eql"
+query = '''
+process where host.os.type == "linux" and event.action == "session_id_change" and event.type == "change" and
+process.name : "kworker*" and user.id == "0"
+'''
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+id = "T1574"
+name = "Hijack Execution Flow"
+reference = "https://attack.mitre.org/techniques/T1574/"
+
+[[rule.threat.technique.subtechnique]]
+id = "T1574.013"
+name = "KernelCallbackTable"
+reference = "https://attack.mitre.org/techniques/T1574/013/"
+
+[rule.threat.tactic]
+id = "TA0004"
+name = "Privilege Escalation"
+reference = "https://attack.mitre.org/tactics/TA0004/"
+
+[[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/"
+