WooCommerce Malware Removal: Rescuing Germany's Largest Bicycle Shop

Client Overview: Leading WooCommerce Bicycle Shop in Germany

The client is one of Germany's largest and most reputable bicycle shops, heavily reliant on their WordPress and WooCommerce-powered e-commerce platform for sales and customer engagement.

The Challenge: Crippling WooCommerce Malware Infection

The client's website suddenly became almost inaccessible, plagued by dozens of Gateway Timeouts. Attempts to access the WordPress Admin Dashboard resulted in a 500 Internal Server Error, effectively locking them out of their own system. This downtime translated directly into lost sales and a damaged reputation.

Initial investigation pointed towards a severe malware infection that had deeply compromised the site's core files and database.

Our Solution: Meticulous Malware Eradication & WooCommerce Security Fortification

As the lead WordPress Developer, my role was to conduct a thorough analysis, identify the full extent of the malware, and implement a robust solution. Our process involved several key stages:

• Deep Malware Scanning & Analysis: Utilized advanced security tools, including Wordfence, to perform comprehensive scans of all files and the database. This identified numerous malicious files and infected core components.
• Manual Code Review: Beyond automated scans, a manual review of theme files, plugins (especially WooCommerce components), and custom code was performed to identify obfuscated malware, backdoors, and vulnerabilities.
  • Check for unauthorized admin users or suspicious code in functions.php and custom plugins.
  • Audit for hidden iframes, base64-encoded payloads, or eval() usage.
  • Review file and directory permissions to prevent unauthorized modifications.
  • Remove unused or outdated plugins/themes to reduce the attack surface.
  • Ensure all user input is sanitized and validated to prevent XSS and SQL injection.
  • Verify that sensitive files (e.g., wp-config.php) are not publicly accessible.
  • Check for hardcoded credentials or API keys in code repositories.
  • Enforce strong password policies and require 2FA for all admin accounts.
  • Disable XML-RPC if not needed and restrict REST API access.
  • Document and regularly review all custom code changes as part of a secure development lifecycle.
• Systematic Malware Removal: Each identified malicious file and code injection was carefully removed or repaired. This included cleaning core WordPress files, theme files, plugins, and database entries.
• WooCommerce Hardening: Specific attention was paid to securing the WooCommerce installation, given its critical role in the client's business. This involved:
  • Updating WordPress core, all plugins, and themes to the latest secure versions
  • Removing unused plugins and themes to reduce the attack surface
  • Enforcing strong, unique passwords and enabling two-factor authentication (2FA) for all admin accounts
  • Disabling XML-RPC and limiting REST API access where not needed
  • Setting secure file permissions (e.g., wp-config.php to 400 or 440)
  • Configuring unique security keys and salts in wp-config.php
  • Implementing a Web Application Firewall (WAF) and enabling brute-force protection
  • Restricting admin access by IP and disabling file editing from the WordPress dashboard
  • Enforcing HTTPS sitewide and updating all internal links to use https://
  • Regularly backing up the site and testing restore procedures
  • Monitoring logs and setting up real-time alerts for suspicious activity
• Security Best Practices Implementation: Post-cleanup, we implemented several security hardening measures, including WAF setup, credential strengthening, and ongoing monitoring protocols.

The investigation also involved examining custom code integrations to ensure their integrity. The snippet below, unrelated to the malware, exemplifies the kind of WordPress functionality reviewed for potential security implications during such an audit.

Key Skills & Deliverables