Network Security Plan (แผนความปลอดภัยเครือข่าย) คืออะไร?
คือ เอกสารแผนงานทางกลยุทธ์และปฏิบัติการ ที่กำหนด นโยบาย กระบวนการ เทคโนโลยี และหน้าที่ความรับผิดชอบ เพื่อ ปกป้อง (Protect), ตรวจจับ (Detect), ตอบสนอง (Respond), และกู้คืน (Recover) เครือข่ายองค์กรจากภัยคุกคาม
ขั้นตอนสร้าง Network Security Plan (Step-by-Step)
Phase 1: Preparation & Assessment (เตรียมและประเมิน)
- Asset Inventory: Hardware, Software, Data, Cloud Assets, Users, Third-parties (CMDB)
- Threat Modeling: Identify Threats (MITRE ATT&CK, CAPEC), Likelihood, Impact
- Risk Assessment: Risk Matrix, Risk Register, Risk Appetite/Tolerance
- Gap Analysis: Current State vs Desired State (NIST CSF, CIS Controls, ISO 27001)
- Regulatory Requirements: PDPA, PCI-DSS, HIPAA, GDPR, Industry-specific
Phase 2: Strategy & Architecture Design (กลยุทธ์และสถาปัตยกรรม)
- Define Security Zones / Segmentation: DMZ, Internal, Server, OT/IoT, Cloud, Management, Guest
- Zero Trust Architecture: Verify Explicitly, Least Privilege, Assume Breach
- Identity & Access Strategy: MFA, PAM, ZTNA, CIEM, Passwordless
- Data Protection Strategy: Encryption (At-rest/In-transit), DLP, Classification, Key Management
- Resiliency & Recovery: HA/DR, Backup (3-2-1), Immutable Backups, RTO/RPO
Phase 3: Policy & Standards Development (นโยบายและมาตรฐาน)
- Network Security Policy (Firewall Rules, ACL, Port/Protocol Allowlist)
- Wireless Security Policy (WPA3, Cert-based Auth, NAC)
- Remote Access / VPN Policy (MFA, Device Compliance, Split Tunneling)
- Vulnerability Management Policy (SLA: Critical 72h, High 30d)
- Incident Response Policy (Roles, Escalation, Communication, Legal)
- Acceptable Use / BYOD / Cloud Usage Policy
Phase 4: Implementation & Deployment (การนำไปใช้)
| Domain | Key Controls / Tools |
|---|---|
| Perimeter | NGFW (App-ID, SSL Decrypt, IPS, URL Filtering, DNS Security), DDoS Protection |
| Network Segmentation | VLAN, VRF, Micro-segmentation (NSX, ACI, Calico, Cilium), East-West FW |
| Access Control | NAC (802.1X, MAB, Posture), ZTNA, PAM, MFA, Conditional Access |
| Monitoring | SIEM (Splunk, Sentinel, Elastic), NTA/NDR (Corelight, Darktrace, Vectra), NetFlow |
| Endpoint | EDR/XDR (CrowdStrike, Defender, SentinelOne), Patch Mgmt, App Control |
| Cloud | CSPM, CWPP, CIEM, CNAPP, CSPM, IaC Scanning, Runtime Protection |
| Data | DLP, Encryption, CASB, DSPM, Key Management (HSM/KMS) |
| Vuln Mgmt | Scanner (Tenable, Qualys, Rapid7), Prioritization (EPSS, KEV), Patch Automation |
Phase 5: Testing & Validation (การทดสอบ - Testing)
- Network Discovery / Port Scanning: Nmap, Masscan - ระบุ Host, Port, Service ทั้งหมด
- Vulnerability Scanning: Authenticated + Unauthenticated Scans (Internal/External)
- Penetration Testing: External, Internal, Wireless, Web App, API, Cloud, Social Engineering
- Red Team / Purple Team Exercise: Simulate APT TTPs (MITRE ATT&CK), Test Detection/Response
- Breach & Attack Simulation (BAS): Automated Continuous Validation (SafeBreach, AttackIQ, Cymulate)
- Password Cracking / Credential Audit: Hashcat, John the Ripper (Authorized Only)
- Configuration Review: Firewall Rule Audit, Hardening Benchmarks (CIS, STIG)
- Wireless Assessment: Aircrack-ng, Kismet, WPA Handshake Capture, Rogue AP Detection
Phase 6: Continuous Monitoring (การเฝ้าระวัง - Monitoring)
- Log Collection & Correlation: SIEM Rules (Sigma, MITRE Mapping), Alert Tuning
- Network Traffic Analysis: Flow Analysis (NetFlow/IPFIX), Encrypted Traffic Analysis (ETA), TLS Fingerprinting (JA3)
- Threat Hunting: Hypothesis-driven, MITRE ATT&CK-based, Scheduled/Ad-hoc
- File Integrity Monitoring (FIM): Critical System Files, Config Files, Registry
- Vulnerability Management Loop: Continuous Scan → Prioritize → Patch → Verify → Report
- Compliance Monitoring: Drift Detection (IaC vs Runtime), Policy as Code (OPA, Sentinel)
- Threat Intelligence Integration: IOC Feeds, TTP Feeds, Actor Tracking, Automated Enrichment
Phase 7: Incident Response & Recovery (ตอบสนองและกู้คืน)
- IR Plan + Playbooks (Phishing, Ransomware, Insider, Cloud, Supply Chain)
- Communication Plan (Internal, External, Legal, Regulatory, Media)
- Forensic Readiness (Log Retention, Disk Imaging, Network PCAP, Chain of Custody)
- Tabletop Exercises (Quarterly), Red Team (Annual)
- Post-Incident Review → Update Plan, Rules, Architecture
5 Essential Requirements for Network & Computer Security
- Positive Identification: User, Host, App, Service, Resource (IAM, NAC, Certificates, mTLS)
- Perimeter Protection: NGFW, IPS, WAF, DDoS, Boundary Control
- Data Privacy: Encryption, DLP, Tokenization, Masking, Access Control
- Security Monitoring: SIEM, NDR, EDR, Cloud Detection, 24/7 SOC
- Policy Management: Centralized, Versioned, Automated Enforcement, Audit Trail
Testing Types สำหรับ Detect Security Faults
| Test Type | Tools | Objective |
|---|---|---|
| Network Discovery | Nmap, Masscan, Angry IP Scanner | Asset Inventory, Attack Surface |
| Vulnerability Scan | Nessus, OpenVAS, Qualys, Tenable.io | Known Vulns (CVE), Misconfig |
| Penetration Test | Metasploit, Cobalt Strike, Burp Suite, BloodHound | Exploitability, Impact, Lateral Movement |
| Red Team | Custom Tooling, C2 (Sliver, Havoc), Tradecraft | Full Kill Chain, Detection/Response Gap |
| Purple Team | Atomic Red Team, Caldera, MITRE ATT&CK | Collaborative Detection Improvement |
| BAS (Automated) | SafeBreach, AttackIQ, Cymulate, XM Cyber | Continuous Validation, Control Effectiveness |
| Wireless Test | Aircrack-ng, Kismet, Wifite, Wireshark | WPA Handshake, Rogue AP, Evil Twin |
| Config Audit | Nipper, kube-bench, kube-hunter, CloudSploit | Hardening Compliance (CIS, STIG) |
Pentest เครือข่ายของตัวเองได้ไหม? (Can I Pentest My Own Network?)
ได้ แต่ต้องมี:
✅ Written Authorization (Rules of Engagement - RoE)
✅ Scope Definition (IP Ranges, Systems, Time Windows, Exclusions)
✅ Rollback/Contingency Plan
✅ Legal/Compliance Review
✅ Stakeholder Notification (IT Ops, Business Owners, Legal)
Framework แนะนำ: PTES (Penetration Testing Execution Standard), OSSTMM, NIST SP 800-115, MITRE ATT&CK
สรุป: Network Security Plan เป็น Living Document
ไม่ใช่เอกสารเขียนทิ้ง ต้อง Review/Update ทุกไตรมาส หรือเมื่อมี:
• การเปลี่ยนแปลง Infrastructure/Major Change
• Incident ใหญ่ / Breach
• Regulation ใหม่ / Audit Finding
• Threat Landscape เปลี่ยน (New TTPs, Zero-days)
• Business Direction เปลี่ยน (M&A, Cloud Migration, New Product)
