Analyzing Web Server Logs for Intrusion

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 user-agents
• Brute force: >50 POST requests to login endpoints from same IP in 5 minutes

1. Enrich with GeoIP data and generate a prioritized findings report.

python scripts/agent.py --log-file /var/log/nginx/access.log --geoip-db GeoLite2-City.mmdb --output web_intrusion_report.json

Examples

Detect SQLi in URI

192.168.1.100 - - [15/Jan/2024:10:30:45 +0000] "GET /products?id=1' UNION SELECT username,password FROM users-- HTTP/1.1" 200 4532

Scanner User-Agent Detection

Nikto/2.1.6, sqlmap/1.7, DirBuster-1.0-RC1, gobuster/3.1.0

Verification Criteria

Confirm successful execution by validating:

• [ ] All prerequisite tools and access requirements are satisfied
• [ ] Each workflow step completed without errors
• [ ] Output matches expected format and contains expected data
• [ ] No security warnings or misconfigurations detected
• [ ] Results are documented and evidence is preserved for audit

Compliance Framework Mapping

This skill supports compliance evidence collection across multiple frameworks:

• SOC 2: CC7.1 (Monitoring), CC7.2 (Anomaly Detection), CC7.3 (Incident Identification)
• ISO 27001: A.12.4 (Logging & Monitoring), A.16.1 (Security Incident Management)
• NIST 800-53: AU-6 (Audit Review), SI-4 (System Monitoring), IR-5 (Incident Monitoring)
• NIST CSF: DE.AE (Anomalies & Events), DE.CM (Continuous Monitoring)

Claw GRC Tip: When this skill is executed by a registered agent, compliance evidence is automatically captured and mapped to the relevant controls in your active frameworks.

Deploying This Skill with Claw GRC

Agent Execution

Register this skill with your Claw GRC agent for automated execution:

# Install via CLI
npx claw-grc skills add analyzing-web-server-logs-for-intrusion

# Or load dynamically via MCP
grc.load_skill("analyzing-web-server-logs-for-intrusion")

Audit Trail Integration

When executed through Claw GRC, every step of this skill generates tamper-evident audit records:

• SHA-256 chain hashing ensures no step can be modified after execution
• Evidence artifacts (configs, scan results, logs) are automatically attached to relevant controls
• Trust score impact — successful execution increases your agent's trust score

Continuous Compliance

Schedule this skill for recurring execution to maintain continuous compliance posture. Claw GRC monitors for drift and alerts when re-execution is needed.