10 Open-Source Security Tools Every Validator Operator Should Run
If you're running validator or RPC infrastructure, your biggest threat isn't just "the hackers" - it's exposure creep.
Ports left open. Containers running ancient versions. Dependencies you forgot existed.
You don't need a SOC team or enterprise budget to stay ahead.
These ten open-source tools will do 80% of the heavy lifting - and they're all battle-tested.
🐇 Looking for External Attack Surface Monitoring?
Most tools monitor the inside. NullRabbit watches from the outside - detecting open ports, SSL misconfigs, and compliance gaps across your validator cluster with agentic, autonomous security intelligence.
NullRabbit Sentinel (Beta) - External exposure scanning for DePIN infrastructure.
🔗 Join the NullRabbit Founding Cohort →
🛠️ 1. Lynis - The Swiss Army Knife for System Audits
Use it for: Hardening checks, privilege audits, kernel & SSH config reviews
Why it matters: Lynis scans your validator host (Linux/macOS/Unix) for 300+ security controls - and gives a clear "score" you can track over time.
sudo lynis audit system
🧱 2. OpenVAS (Greenbone Vulnerability Manager)
Use it for: Scheduled scans of your node's public interfaces
Why it matters: Detects thousands of CVEs using up-to-date NVT feeds. You can schedule recurring scans on your node subnet or cloud range.
🔗 https://www.greenbone.net/en/community-edition/
🚪 3. Fail2Ban - Brute-Force Defence That Actually Works
Use it for: SSH, API, or RPC login protection
Why it matters: Watches log files for failed login attempts and bans offending IPs. Simple, low overhead, and essential for exposed ports.
🧩 4. CrowdSec - Collaborative Intrusion Prevention
Use it for: Shared threat intelligence between node operators
Why it matters: Think Fail2Ban 2.0 - it blocks malicious IPs in real time and shares intel with a global network of defenders.
🕵️♂️ 5. OSQuery - Query Your Infrastructure Like a Database
Use it for: Runtime visibility with SQL (processes, ports, users)
Why it matters: Instead of grepping logs, ask questions like:
SELECT * FROM listening_ports WHERE port > 1000;
Perfect for spotting rogue daemons or config drift across nodes.
🔗 https://osquery.io/
📊 6. Netdata - Real-Time Infra Monitoring Without the Bloat
Use it for: System metrics, network I/O, CPU anomalies
Why it matters: Lightweight but visually rich dashboards. Self-hosted. Real-time. No data leaves your infra.
🌐 7. Zmap + Nmap - The Network Recon Twins
Use it for: Fast port discovery & deep service identification
Why it matters: Use Zmap for sweeping large IP ranges fast, then feed results to Nmap for deeper probes.
zmap -p 22,80,443 your.ip.range | nmap -A -iL -
🔗 https://zmap.io/ / https://nmap.org/
🧰 8. Trivy - The Container Vulnerability Scanner
Use it for: Scanning Docker images & dependencies
Why it matters: If your validator runs inside containers, Trivy scans both OS packages and language libs.
trivy image your-validator:latest
🔗 https://aquasecurity.github.io/trivy/
📈 9. Prometheus + Grafana - The Gold Standard for Metrics
Use it for: Exporting validator metrics, alerting, and dashboards
Why it matters: Every serious operator uses these. Combine with node exporter, blackbox probes, or chain-specific exporters (Sui, Cosmos, etc.).
🔗 https://prometheus.io/ / https://grafana.com/
🛡️ 10. Wazuh - Host Intrusion Detection + SIEM
Use it for: Centralized log analysis, file integrity monitoring, rootkit detection
Why it matters: Wazuh aggregates logs from all your tools, monitors file changes on validators, detects rootkits, and provides compliance reporting. Your security ops center in a box.
⚙️ How to Run Them Together
| Category | Tool(s) | Schedule |
|---|---|---|
| OS Hardening | Lynis | Weekly |
| Port Scanning | Zmap + Nmap | Daily |
| Intrusion Prevention | Fail2Ban / CrowdSec | Continuous |
| Container Scanning | Trivy | On deploy |
| Infra Monitoring | Netdata / Prometheus | Always |
| SIEM & FIM | Wazuh | Continuous |
💡 Pro tip: Feed Trivy or Nmap JSON results into Wazuh for correlated security events across your infrastructure.
🧭 Final Thought
Most validators don't fail because of big exploits - they fail from basic hygiene drift.
Automate your scanning, run these weekly, and sleep better.