[New] SOCKS Traffic from an Unusual Process (#5324)

* [New] SOCKS Traffic from an Unusual Process

This detection correlates FortiGate's application control SOCKS events with Elastic Defend network event to identify the
source process performing SOCKS traffic. Adversaries may use a connection proxy to direct network traffic between systems
or act as an intermediary for network communications to a command and control server to avoid direct connections to their
infrastructure.

* Update command_and_control_socks_fortigate_endpoint.toml

* Update command_and_control_socks_fortigate_endpoint.toml

* Update rules/cross-platform/command_and_control_socks_fortigate_endpoint.toml

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update command_and_control_socks_fortigate_endpoint.toml

* add fortinet schema and manif

* Update rules/cross-platform/command_and_control_socks_fortigate_endpoint.toml

Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>

* Update rules/cross-platform/command_and_control_socks_fortigate_endpoint.toml

Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>

* Update pyproject.toml

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "detection_rules"
-version = "1.5.13"
+version = "1.5.14"
 description = "Detection Rules is the home for rules used by Elastic Security. This repository is used for the development, maintenance, testing, validation, and release of rules for Elastic Security’s Detection Engine."
 readme = "README.md"
 requires-python = ">=3.12"

rules/cross-platform/command_and_control_socks_fortigate_endpoint.toml

@@ -0,0 +1,85 @@
+[metadata]
+creation_date = "2025/11/17"
+integration = ["endpoint", "fortinet_fortigate"]
+maturity = "production"
+updated_date = "2025/11/17"
+
+[rule]
+author = ["Elastic"]
+description = """
+This detection correlates FortiGate's application control SOCKS events with Elastic Defend network event to identify the
+source process performing SOCKS traffic. Adversaries may use a connection proxy to direct network traffic between systems
+or act as an intermediary for network communications to a command and control server to avoid direct connections to their
+infrastructure.
+"""
+from = "now-9m"
+index = ["logs-endpoint.events.network-*", "logs-fortinet_fortigate.log-*"]
+language = "eql"
+license = "Elastic License v2"
+name = "SOCKS Traffic from an Unusual Process"
+references = [
+    "https://attack.mitre.org/techniques/T1090/",
+    "https://www.elastic.co/docs/reference/integrations/fortinet_fortigate",
+    "https://www.elastic.co/docs/reference/integrations/endpoint"
+]
+risk_score = 47
+rule_id = "6926b708-7964-425f-bed8-6e006379df08"
+severity = "medium"
+tags = [
+    "Domain: Endpoint",
+    "OS: Linux",
+    "OS: Windows",
+    "OS: macOS",
+    "Use Case: Threat Detection",
+    "Tactic: Command and Control",
+    "Data Source: Elastic Defend",
+    "Data Source: Fortinet",
+    "Resources: Investigation Guide",
+]
+type = "eql"
+query = '''
+sequence by source.port, source.ip, destination.ip with maxspan=1m
+ [network where event.dataset == "fortinet_fortigate.log" and event.action == "signature" and network.application in ("SOCKS4", "SOCKS5")]
+ [network where event.module == "endpoint" and event.action in ("disconnect_received", "connection_attempted")]
+'''
+note = """## Triage and analysis
+
+### Investigating SOCKS Traffic from an Unusual Process
+
+### Possible investigation steps
+
+- Review the process details like command_line, privileges, global relevance and reputation.
+- Review the parent process execution details like command_line, global relevance and reputation.
+- Examine all network connection details performed by the process during last 48h.
+- Examine all localhost network connections performed by the same process to verify if there is any port forwarding with another process on the same machine.
+- Correlate the alert with other security events or logs to identify any patterns or additional indicators of compromise related to the same process or network activity.
+
+### False positive analysis
+
+- Browser proxy extensions and Add-ons.
+- Development and deployment tools.
+- Third party trusted tools using SOCKS for network communication.
+
+### Response and remediation
+
+- Immediately isolate the affected system from the network to prevent further unauthorized access or data exfiltration.
+- Terminate the suspicious processes and all associated children and parents.
+- Conduct a thorough review of the system's configuration files to identify unauthorized changes.
+- Reset credentials for any accounts associated with the source machine.
+- Implement network-level controls to block traffic via SOCKS unless authorized.
+- Escalate the incident to the security operations center (SOC) or incident response team for further investigation and to determine if additional systems are affected.
+"""
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+id = "T1090"
+name = "Proxy"
+reference = "https://attack.mitre.org/techniques/T1090/"
+
+
+[rule.threat.tactic]
+id = "TA0011"
+name = "Command and Control"
+reference = "https://attack.mitre.org/tactics/TA0011/"