Analyzing Web Server Logs for Intrusion

When to Use

• When investigating security incidents that require analyzing web server logs for intrusion
• When building detection rules or threat hunting queries for this domain
• When SOC analysts need structured procedures for this analysis type
• When validating security monitoring coverage for related attack techniques

Prerequisites

• Familiarity with security operations concepts and tools
• Access to a test or lab environment for safe execution
• Python 3.8+ with required dependencies installed
• Appropriate authorization for any testing activities

Instructions

1. Install dependencies: pip install geoip2 user-agents
2. Collect web server access logs in Combined Log Format (Apache) or Nginx default format.
3. Parse each log entry extracting: IP, timestamp, method, URI, status code, response size, user-agent, referer.
4. Apply detection rules:
   • SQL injection: UNION SELECT, OR 1=1, ' OR ', hex encoding patterns
   • LFI/Path traversal: ../, /etc/passwd, /proc/self, php://filter
   • XSS: <script>, javascript:, onerror=, onload=
   • Scanner signatures: nikto, sqlmap, dirbuster, gobuster, wfuzz …