The guidance document, prepared by leading cybersecurity agencies across the Five Eyes alliance, addresses the growing threat of cyber espionage campaigns by PRC-affiliated actors targeting global telecommunications providers. The document highlights critical vulnerabilities in communications infrastructure and provides best practices to enhance visibility, harden systems, and defend against cyber exploitation.
Key Objectives
The primary focus of the document is to assist network engineers and defenders in securing network devices, improving monitoring capabilities, and implementing a defense-in-depth strategy. While tailored for communications infrastructure, the guidance is also relevant to organizations with on-premises enterprise equipment.
Enhancing Visibility
Visibility is described as the cornerstone of effective cybersecurity, enabling organizations to monitor, detect, and understand activity within their networks. The guidance emphasizes:
- Comprehensive Monitoring: Implement solutions to scrutinize network traffic, detect configuration changes, and identify anomalies. Centralized logging with secure encryption, integration with SIEM tools, and maintaining an updated inventory of devices are recommended.
- Proactive Detection: Establish baselines for normal network behavior and define alert rules to flag abnormal activities. Monitor user and service account logins for unauthorized access or malicious activity.
- Network Flow Visibility: Strategic placement of flow data exporters at ingress and egress points to capture detailed insights into inter-customer traffic and network events.
Hardening Systems and Devices
The guide outlines a defense-in-depth strategy aimed at reducing vulnerabilities and strengthening network security through:
- Out-of-Band Management: Isolating management networks from operational data flow to limit lateral movement in case of compromise.
- Network Segmentation: Using firewalls, ACLs, and VLANs to create logical separation between device groups and isolate critical services in a DMZ.
- Protocol and Cryptography Hardening: Mandating TLS 1.3, AES-256 encryption, and authenticated protocols like SNMP v3 while disabling weaker protocols such as Telnet and FTP.
- Access Controls: Enforcing Role-Based Access Control (RBAC) and applying the principle of least privilege to minimize access risks.
Collaboration Between Engineers and Defenders
The document underscores the importance of close collaboration between network engineers and defenders. Key recommendations include:
- Conducting regular audits and compliance checks of networking configurations.
- Monitoring for vendor end-of-life announcements and applying timely patches.
- Implementing robust change and patch management processes.
- Securing credentials with modern hashing techniques and enforcing phishing-resistant multi-factor authentication for all accounts.
Conclusion
By integrating the outlined visibility enhancements and hardening practices, telecommunications providers and critical infrastructure organizations can fortify their defenses against sophisticated cyber threats. This guidance is a critical resource for mitigating vulnerabilities and maintaining secure and resilient communications infrastructure.