Metzler Webshield

Metzler_Webshield is a lightweight security and Web Application Firewall (WAF) plugin for WordPress. It is designed to have minimal impact on server performance by utilizing a Must-Use (MU) plugin architecture and offloading threat intelligence to a centralized API.

Features

• Real-Time WAF: Intercepts requests early in the WordPress boot process to block SQL Injection (SQLi), Cross-Site Scripting (XSS), and malicious bot traffic.
• Malware Scanner: Scans the local filesystem for known malware signatures, webshells, and backdoors.
• File Integrity Monitoring (FIM): Creates a baseline of WordPress core and plugin files to detect unauthorized modifications.
• Smart Quarantine: Isolates suspicious files into a secure sandbox with a one-click restoration option.
• GDPR-Compliant: Does not track legitimate website visitors. Threat telemetry is restricted to blocking data of active attackers (Art. 6(1)(f) GDPR).

Architecture

To prevent database bloat and excessive server load, Metzler_Webshield operates on a split-logic model:

1. The Plugin (GPLv2): The local WordPress client handles request interception (via an MU-Plugin), local file scanning, and the native WordPress UI.
2. The API (Proprietary Service): Threat intelligence, IP blocklists, and malware signatures are maintained centrally on the Metzler_Webshield API (api.metzler-webshield.de). The plugin communicates with this API to receive the latest security definitions.

Installation

1. Upload the metzler-webshield folder to your /wp-content/plugins/ directory.
2. Activate the plugin via the WordPress Admin panel.
3. Navigate to the Metzler_Webshield menu in the dashboard.
4. Request and verify a license key via your email address to enable the API connection.
5. The MU-Plugin will automatically be deployed to /wp-content/mu-plugins/.

License & Terms

The PHP source code of this WordPress plugin is licensed under the GNU General Public License v2.0.

Note on API Usage: While the plugin code is open-source, the Metzler_Webshield Threat Intelligence API is a proprietary service. The use of the API, threat definitions, and network infrastructure is subject to the Metzler_Webshield Terms of Service. A valid license key is required to access the API.

Branding Guidelines

The "Metzler_Webshield" name and logo are the exclusive branding of Metzler Webseiten. If you choose to fork or distribute a modified version of this plugin, you must remove all Metzler_Webshield branding and logos.