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Elastic Docs ›Elastic Security [8.19] ›Detections and alerts ›Prebuilt rule reference

SOCKS Traffic from an Unusual Process

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SOCKS Traffic from an Unusual Process

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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.

Rule type: eql

Rule indices:

  • logs-endpoint.events.network-*
  • logs-fortinet_fortigate.log-*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

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

Version: 1

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

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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 query

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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")]

Framework: MITRE ATT&CKTM

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