Plesk · Server Security · Zero Config

Server security for Plesk

Defensia runs alongside Plesk Obsidian's native tools. It auto-discovers all your vhost access logs, extends fail2ban's basic protection with a full WAF engine, scans vhost directories for malware, and surfaces CVE advisories — all from a single dashboard.

Start Free
Standard Install — root@your-plesk-server1 command
$ curl -fsSL https://defensia.cloud/install.sh | sudo bash
# Agent auto-detects Plesk vhost structure on first run
# Discovers /var/www/vhosts/system/*/logs/access_log
# No Plesk extension or API key required

What Defensia adds to your Plesk server

Complementary security — not a replacement for Plesk, a deep extension of it.

📁

Plesk vhost log monitoring

Auto-discovers every domain under /var/www/vhosts/system/*/logs/access_log. Full OWASP WAF engine applied to each domain — SQL injection, XSS, RCE, and path traversal detection with per-request scoring.

🔐

SSH brute force protection

Monitors /var/log/auth.log (Debian/Ubuntu) and /var/log/secure (RHEL/CentOS) for failed SSH logins including Plesk SSH users. Escalating bans with configurable thresholds.

🛡

Fail2ban upgrade

Plesk ships fail2ban but it's reactive and config-heavy. Defensia adds WAF-scored bans, a real-time dashboard, cross-server ban propagation, and CVE-aware context that fail2ban can't provide.

🌍

Web Application Firewall

OWASP Core Rule Set engine scored per request per domain. Detects SQLi, XSS, RCE, SSRF, path traversal, .env probing, and scanner fingerprints (sqlmap, nikto, nuclei). Works with both nginx and Apache proxies.

🔍

Malware scanner

Recursively scans all vhost directories (/var/www/vhosts/) for backdoors, web shells, and injected PHP. Detects obfuscated code, base64 payloads, and known malware signatures. Real-time progress per domain.

📋

CVE advisory scanner

Checks all installed packages against NVD + EPSS + CISA KEV databases. Surfaces exploitable CVEs affecting your Plesk version, PHP builds, and OS packages with severity and patch guidance.

Automatic vhost log discovery

Plesk stores per-domain logs under /var/www/vhosts/system/. Defensia finds and monitors every one — no configuration needed.

/var/www/vhosts/system/example.com/logs/access_log34 events today
/var/www/vhosts/system/shop.example.com/logs/access_log112 events today
/var/www/vhosts/system/clientsite.net/logs/access_log7 events today
/var/www/vhosts/system/api.saasapp.io/logs/access_log203 events today
/var/www/vhosts/system/blog.agency.com/logs/access_log18 events today

HTTPS log variants (proxy_access_ssl_log) auto-merged. New domains added in Plesk are detected automatically — no agent restart needed.

Plesk's built-in security vs Defensia

Plesk ships solid baseline security. Defensia fills the gaps that Plesk's native tools don't cover.

WHAT PLESK INCLUDES NATIVELY
  • Fail2ban (basic)Ships pre-configured, protects SSH and Plesk panel login. No dashboard, no WAF scoring.
  • ModSecurity (optional extension)Available as a paid Plesk extension. Requires manual rule set management. No unified dashboard.
  • SSL/TLS managementLet's Encrypt auto-renewal and certificate management via Plesk UI.
  • Firewall (basic)iptables rule management via Plesk panel. Port-level only, no application-layer inspection.
  • ImunifyAV (scan only)Free malware scanner included in Plesk Obsidian, but clean-up and real-time protection require paid upgrade.
WHAT DEFENSIA ADDS
  • Real-time WAF dashboardEvery blocked request logged with attack type, OWASP score, IP reputation, and country.
  • WAF scoring per domainPer-request risk score across 15 attack categories. Tune thresholds per domain without config files.
  • Full malware scan with progressReal-time scan progress per vhost directory. Backdoors, shells, and injected code detected with YARA.
  • CVE tracking (NVD + EPSS + CISA KEV)Know which installed packages have exploitable vulnerabilities before attackers do.
  • Alerts (Slack, email, webhook)Instant notification on ban, malware detection, CVE match, or server going offline.
  • Multi-server unified dashboardAll Plesk servers, all domains, all events in one place. Security score per server.

Plesk Security Extensions vs Defensia

Imunify360 and Plesk's own ModSecurity extension are the common alternatives. Here's how they compare.

FeatureDefensiaPlesk ModSecurity Ext.Imunify360
Price (per server)€9/mo~$10/mo (ext.)$12–45/mo
Plesk requiredNo (any Linux)YesYes (cPanel/Plesk)
Vhost log auto-discoveryYesNoYes
WAF engineOWASP CRS scoringModSecurity (manual)ModSecurity
SSH brute force15 patterns + journaldVia fail2banPAM module
Malware scannerFull (YARA + signatures)ImunifyAV (basic)Full (paid)
CVE scanningNVD + EPSS + CISA KEVNoNo
Real-time dashboardIncludedPlesk panel onlyIncluded
Multi-server viewIncludedNoSeparate product
Open source agentYes (MIT)NoNo

Full protection for Plesk servers

Every layer of a Plesk server covered — web, system access, and ongoing vulnerability tracking.

WEB

WAF + Bot detection

  • Per-domain OWASP WAF scoring
  • SQL injection, XSS, RCE, SSRF
  • Path traversal + .env probing
  • Bot fingerprinting (sqlmap, nikto, nuclei)
  • WordPress login + xmlrpc.php protection
SYSTEM

SSH + Malware

  • SSH brute force (15 patterns)
  • auth.log + journald monitoring
  • Malware scan across all vhost dirs
  • YARA signatures + obfuscation detection
  • Escalating bans with auto-expiry
MONITORING

CVE + Alerts

  • NVD + EPSS vulnerability matching
  • CISA KEV exploitable CVE flagging
  • Slack, email, webhook alerts
  • Server offline notifications
  • Compliance hardening score

Frequently asked questions

Does Defensia conflict with Plesk's built-in fail2ban?

No. Defensia and Plesk's fail2ban instance run independently. Defensia does not touch fail2ban's jail.conf or its iptables rules. Both can protect SSH simultaneously. You can disable Plesk fail2ban if you want to simplify, or leave both running — there is no conflict.

Does Defensia work with Plesk's nginx + Apache proxy setup?

Yes. Plesk Obsidian uses nginx as a reverse proxy in front of Apache by default. Defensia reads the access_log files that Apache writes — these contain the real client IPs including Plesk's X-Forwarded-For headers. The WAF engine parses both CLF and combined log formats automatically.

What log path does Defensia use for Plesk vhosts?

Defensia globs /var/www/vhosts/system/*/logs/access_log and also picks up proxy_access_ssl_log variants. Both HTTP and HTTPS traffic is covered. New domains added in Plesk are detected on the next polling cycle — no restart required.

Does Defensia require a Plesk extension or API access?

No. The Defensia agent is a standard Go binary that runs as a systemd service. It reads log files directly from the filesystem. No Plesk API key, no extension marketplace installation, and no Plesk panel access is needed.

Can Defensia detect web shells uploaded via Plesk File Manager?

Yes. The malware scanner recursively scans /var/www/vhosts/ on demand or on schedule. It detects obfuscated PHP, base64-encoded payloads, known web shell signatures, and injected eval() chains — regardless of how the file was uploaded.

Does it work on both Plesk for Linux and Plesk for Windows?

The current Defensia agent supports Linux only (Debian, Ubuntu, RHEL, CentOS, AlmaLinux, and Rocky Linux). Plesk for Windows is not supported at this time.

How does the CVE scanner handle Plesk-specific packages?

The agent queries the system package manager (apt or rpm) to enumerate installed software and versions. This includes Plesk-distributed PHP builds, Plesk panel packages (plesk-core, sw-cp-server), and all OS packages. Matches run against NVD, EPSS, and CISA's Known Exploited Vulnerabilities catalog.

What about ImunifyAV that comes with Plesk Obsidian?

ImunifyAV is bundled with Plesk Obsidian and provides basic malware scanning (detection only — removal requires a paid upgrade). Defensia's malware scanner runs independently, supports YARA rules, and is included in the Pro plan alongside the WAF, CVE tracking, and alerts. No separate scanner subscription needed.

Protect your Plesk server in 30 seconds

One command. The agent finds all your vhosts, activates the WAF, and starts monitoring — no Plesk extension, no API key, no configuration file to edit.

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