Terminal Security: Risks, Detection, and Defense Strategies

In today’s digital workplace, terminal security has become a critical concern for enterprises. Let’s break down the key risks, detection methods, and defense technologies to safeguard your organization’s endpoints.
Terminal Security Risks: Why Endpoints Are Vulnerable
For most enterprises, over 90% of employees rely on PC terminals for daily work, making terminals vital nodes for data exchange with the internet . Alarmingly, 80% of security incidents in enterprise networks originate from these endpoints, which have become prime targets for hackers .

Hackers aim to steal valuable data. Once they gain control of a terminal, they can plant ransomware or use the compromised device as a 跳板 to launch internal attacks on critical servers storing sensitive information . A major threat comes from botnets—networks of hacked devices controlled by hackers via viruses, trojans, or worms. Botnets enable information theft, redirect users to phishing sites, and even facilitate advanced persistent threats (APT attacks) through stealthy infiltration, surveillance, and data theft . Their harms include hidden risks, sensitive data leakage, and local infiltration across networks .
Terminal Security Detection and Defense Technologies
Traditional defenses like firewalls or simple authentication are no longer sufficient, as "trusted" users or traffic can still hide malicious intent . Modern solutions focus on proactive and granular control:

Deep Packet Inspection (DPI) at Layer 7: This technology enables comprehensive terminal security by analyzing application-layer traffic, ensuring visibility and control over network activities .
Visualized Application Management: By identifying applications and managing traffic, enterprises can prioritize bandwidth for core services (e.g., OA, SAP) while blocking or limiting non-essential or risky apps (e.g., illegal downloads, online games) .
Dual-Directional Access Control: Security tools like NGAF enforce default "deny-all" policies, with two types of control strategies:
Application-based control: Filters traffic by matching packet signatures, requiring a certain volume of data to identify the application before taking action .
Service-based control: Uses five-tuple matching (source/destination IP, ports, and protocol) for immediate interception of suspicious traffic .
Web Filtering: Blocks risky content via URL and file filtering, covering both HTTP (GET/POST) and HTTPS traffic to prevent access to phishing or malicious websites .
Gateway Antivirus: A First Line of Defense
Computer viruses—self-replicating code that damages systems or data—pose ongoing threats . Traditional antivirus software is passive, relying on updated virus libraries, leaving gaps if any terminal fails to update .

Gateway antivirus strengthens defenses by scanning incoming data at the network perimeter, blocking viruses before they infiltrate internal systems . Its advantages include:

Application-layer virus filtering and bidirectional gateway traffic scanning .
Proactive defense outside the network, easy deployment, and low maintenance .
Integration with endpoint antivirus software for multi-layered protection .

It uses two detection methods: proxy scanning (caching files for in-depth analysis) and stream scanning (matching file signatures against local libraries) . Configuration involves defining policies, targeting users/IP groups, selecting protocols (HTTP, SMTP, FTP), and specifying file types to scan -.
Botnet Detection and Defense: Combating Stealthy Threats
Botnets—networks of compromised devices—are often used in APT attacks, making traditional antivirus tools ineffective . Effective defense requires:

Post-Incident Detection: Identifying infected devices and maintaining traceable logs to reduce risks . Security tools like NGAF detect malicious traffic from botnets, block communications, and log events .
Malicious Link Blocking: Uses blacklists/whitelists for initial filtering; unknown links are analyzed via cloud sandboxing, with updated rules pushed to the gateway .
Cloud Sandbox Analysis: Suspicious traffic is uploaded to the cloud for behavioral analysis (process, file, network, and registry activities), generating security rules for real-time updates -.
Anomaly Traffic Monitoring: Detects deviations from normal behavior, such as unusual port usage, one-way traffic, or DDoS attacks (e.g., SYN/ICMP floods) .
Extensive Rule Libraries: With over 400,000 botnet detection rules, these systems identify known threats like trojans and malware variants .

By combining these technologies—endpoint protection, gateway antivirus, and botnet monitoring—enterprises can build a robust defense against evolving terminal threats, safeguarding data and network integrity.