Vultr Firewall blocks ports. But it cannot detect SSH brute force patterns, SQL injection in your web logs, or malware on disk. Defensia fills every gap Vultr Firewall leaves open — across all 32 data center locations.
Secure your Vultr VPS in 30 seconds →Every public-facing Vultr instance is discovered by automated botnets within minutes of deployment. Vultr's 32 data center locations span six continents, which means your server is reachable from nearly every attack source on the internet. Based on Defensia telemetry, a new VPS receives its first SSH brute force attempt within 22 minutes. The average server sees 4,200+ attacks per day — failed password attempts, web vulnerability scans, credential stuffing bots, and port probes. For a comprehensive hardening walkthrough, see our guide on how to secure a Linux server.
sshd[4821]: Failed password for root from 185.220.101.7 port 43992 ssh2
sshd[4823]: Invalid user admin from 45.83.64.11 port 55120 ssh2
sshd[4825]: pam_unix(sshd:auth): authentication failure; rhost=103.145.13.90
sshd[4827]: Failed password for invalid user ubuntu from 92.118.39.18 port 22180
sshd[4830]: Disconnected from authenticating user root 45.83.64.11 port 38204 [preauth]
... thousands more today. Every Vultr instance gets this.
Vultr Firewall is a solid network-level filter — it blocks ports you do not need open. But it provides no traffic logs, performs zero application-layer inspection, and cannot tell you that someone is brute-forcing root on port 22, injecting SQL through your web app, or uploading a PHP shell to your WordPress site. You need an active security layer that watches, detects, and responds — and that is exactly what Defensia provides.
Vultr is a developer-friendly cloud provider with global reach — 32 locations, competitive pricing, and a clean API. But infrastructure security and host-level security are two different things. Here is what Vultr provides natively and what it does not.
| Security layer | Vultr | Defensia |
|---|---|---|
| Network firewall | Vultr Firewall (free) | iptables/ipset (automatic, unlimited) |
| Firewall logs / traffic visibility | ✗ | Full event log + dashboard |
| SSH brute force detection | ✗ | 15 patterns, auto-ban |
| Web Application Firewall (WAF) | ✗ | 15+ OWASP types from nginx/Apache logs |
| Malware scanning | ✗ | 64K+ hash signatures + 684 patterns |
| CVE / vulnerability scanning | ✗ | NVD + EPSS + CISA KEV |
| DDoS protection | L3/L4 only (free) | L7 via WAF log analysis |
| Server monitoring | ✗ | Security events + attacks + posture score |
| Geoblocking | ✗ | 200+ countries at firewall level |
| Bot management | ✗ | 70+ fingerprints, per-policy |
| Real-time attack dashboard | ✗ | ✓ |
| Private networking (VPC 2.0) | ✓ | ✗ |
| Managed Kubernetes (VKE) | ✓ | ✗ |
| Automatic backups | ✓ | ✗ |
Credit where it is due: Vultr provides free DDoS protection (L3/L4), private networking (VPC 2.0), automatic backups, SSH key authentication, managed Kubernetes (VKE), managed databases, and block storage. Their global network spans 32 locations across six continents. Defensia builds the security monitoring layer on top — the part Vultr intentionally does not provide.
One command. Works on every Vultr instance — Cloud Compute, High Frequency, High Performance, and Bare Metal. Supports Ubuntu, Debian, Rocky Linux, AlmaLinux, Fedora, and CentOS. No packages to install, no dependencies, no configuration files. The agent auto-detects your operating system, log paths, and running services.
# What happens on your Vultr instance:
1. Downloads the Go binary (~15MB) for your architecture (amd64 or arm64)
2. Installs to /usr/local/bin/defensia-agent
3. Creates a systemd service unit
4. Auto-detects SSH log path (/var/log/auth.log on Ubuntu, journald on Rocky/Alma)
5. Auto-detects nginx/Apache access logs if present
6. Starts protecting immediately — no config files to edit
Defensia works alongside Vultr Firewall — they complement each other. Vultr Firewall filters traffic at the network level before it reaches your instance. Defensia detects attacks within the traffic that the firewall allows through. Keep Vultr Firewall enabled to block unused ports, and let Defensia handle application-layer threats. The agent is a single Go binary with zero dependencies, uses under 30MB of RAM, and works on Vultr instances starting from $2.50/month. You can also add Defensia to Vultr's startup script to auto-install on every new instance you deploy.
Six detection engines cover every attack surface on your VPS — from SSH to web applications to the filesystem.
Vultr instances across 32 global locations are continuously scanned by botnets. Defensia reads /var/log/auth.log (Ubuntu, the most popular Vultr OS) or journald (Rocky/Alma) and detects 15 SSH attack patterns: failed passwords, invalid users, pre-auth disconnects, PAM failures, and key exchange drops. Attackers are blocked within seconds via ipset.
Deep dive into SSH protection →Vultr Firewall allows traffic on ports 80 and 443 — it has to. Defensia reads nginx and Apache access logs and detects SQL injection, XSS, path traversal, RCE, SSRF, shellshock, and 10+ more OWASP attack types within that allowed traffic. Zero configuration required — log paths are auto-detected.
See WAF detection details →Vultr has no file-level scanning. Defensia scans the filesystem with 64,000+ hash signatures and 684 dynamic patterns. Detects PHP backdoors in WordPress upload directories, obfuscated shells, cryptominers in /tmp and /dev/shm, and modified system binaries. Critical for Vultr instances running web applications open to the internet.
Matches installed packages (apt on Ubuntu, rpm on Rocky/Alma) against the National Vulnerability Database. Each CVE is scored with EPSS exploit probability and flagged if it appears in the CISA Known Exploited Vulnerabilities catalog. Vultr does not provide any vulnerability scanning — Defensia fills this gap completely.
70+ bot fingerprints identified from User-Agent strings and request patterns. Legitimate bots (Googlebot, Bingbot) are allowed. Vulnerability scanners, credential stuffing bots, and scrapers are blocked or logged per your policy. Particularly valuable for Vultr instances serving web applications across multiple global locations.
Continuous assessment of your VPS security: SSH configuration, firewall rules, file permissions, world-readable credentials, exposed .git directories, and weak key permissions. Scored 0-100 with A-F grade. Provides actionable recommendations specific to your server configuration — the security audit Vultr does not offer.
Vultr handles infrastructure — compute, networking, storage, managed databases, managed Kubernetes, and a global edge network. Defensia handles host-level security — attack detection, automated blocking, malware scanning, vulnerability management, and real-time monitoring. Together, they form a complete stack across all 32 Vultr locations.
Defensia is not a replacement for Vultr Firewall — it is the security layer that sits on top. Vultr Firewall decides which ports are open. Defensia monitors what happens on those open ports and blocks malicious actors automatically. A Vultr Cloud Compute instance ($6/month) plus Defensia Pro (EUR 9/month) gives you a fully secured server for under $16/month — with global reach across any of Vultr's 32 locations.
Running Vultr Kubernetes Engine? Defensia deploys as a DaemonSet via Helm chart — one agent per worker node. The agent monitors ingress controller logs for web attacks, detects SSH brute force on nodes, and scans for malware across the cluster. VKE provides a free control plane; Defensia adds the security layer that VKE does not include.
# Deploy on VKE:
$ helm repo add defensia https://defensia.cloud/charts
$ helm install defensia-agent defensia/defensia-agent \
--set apiKey=YOUR_API_KEY
Killer feature: Defensia reads ingress controller logs (nginx-ingress, Traefik) and detects web attacks across all services behind the ingress — one agent protects your entire cluster. Read the full Kubernetes security guide.
Three steps: (1) Enable Vultr Firewall to block unused ports. (2) Use SSH keys instead of password authentication. (3) Install Defensia with one command — curl -fsSL https://defensia.cloud/install.sh | sudo bash — to get SSH brute force protection, WAF, malware scanning, CVE detection, and a real-time dashboard. Defensia handles everything that Vultr Firewall and SSH keys cannot.
Yes, they complement each other perfectly. Vultr Firewall filters traffic at the network level before it reaches your instance — blocking ports you do not need open. Defensia detects application-level attacks within the traffic that Vultr Firewall allows through: SSH brute force on port 22, SQL injection on port 443, malware on disk. There is no conflict between them. Keep both enabled.
Defensia has been submitted to the Vultr Marketplace and is pending approval. In the meantime, you can install Defensia on any Vultr instance with a single curl command. You can also add the install command to a Vultr startup script to auto-deploy Defensia on every new instance.
Yes. Deploy Defensia via Helm chart as a DaemonSet — one agent per worker node. The agent monitors ingress controller logs for web attacks, detects SSH brute force, scans for malware, and checks for CVEs across all nodes. VKE provides a free control plane; Defensia adds the security monitoring that VKE does not include.
Defensia is free for 1 server — includes SSH protection, the full real-time dashboard, and bot detection. Pro costs EUR 9/server/month (EUR 7 billed annually) and adds WAF, malware scanning, CVE intelligence, geoblocking, and alerts. A $6/month Vultr instance plus EUR 9 Defensia Pro is roughly $16/month for a fully secured VPS.
Yes. Defensia works on any Linux server with systemd and iptables — including Vultr Bare Metal servers. The install is the same one-command process. Bare Metal servers benefit especially from malware scanning and CVE detection due to their longer uptime and larger attack surfaces.
Vultr Firewall features (network-level, no logs, no application-layer inspection) based on official documentation: docs.vultr.com/vultr-firewall.
Vultr pricing (Cloud Compute from $2.50/month) and data center locations (32 worldwide) based on vultr.com/pricing and vultr.com/features/datacenter-locations as of April 2026.
Vultr DDoS protection (L3/L4) and VPC 2.0 features based on official product pages: vultr.com/products/ddos-protection and docs.vultr.com/vpc.
Attack frequency and time-to-first-attack metrics based on Defensia telemetry data across production servers monitored from January to April 2026.
Vultr Kubernetes Engine (VKE) features based on vultr.com/kubernetes as of April 2026.
Complete guide for all Linux distributions.
Protect your Droplets and DOKS clusters.
Cloud and dedicated servers in Europe.
VKE, EKS, GKE — Helm chart DaemonSet.
15 detection patterns, ipset blocking.
OWASP attack detection from server logs.
One command. Under 30 seconds. Works on every Vultr instance across all 32 global locations.
No credit card required. Free for 1 server.