A recent discovery reveals a malicious plugin injected into a WordPress/WooCommerce ecommerce website, demonstrating a dual threat. The malicious code not only creates a deceptive administrator user but also injects sophisticated credit card skimming JavaScript into the website’s checkout page, posing a significant risk to both site owners and users. The malware is introduced into the environment by being lodged into a specific file, ‘mu-plugins/wp_services.php,’ concealing itself as a seemingly legitimate plugin related to WordPress Cache Addons. Once installed, it replicates itself into the ‘mu-plugins’ directory, which doesn’t require user activation and is automatically executed by WordPress.
The malware employs tactics to hinder detection and removal, including obfuscating the injection location and restricting the usage of file manager plugins, making it challenging for website administrators to eliminate the threat easily. Apart from its concealment techniques, the malware engages in creating and concealing an administrator user account, providing the attackers with sustained access to the environment while hiding from legitimate website administrators.
This tactic reduces the total admin count in the panel, making it less noticeable to site owners. Additionally, the malware goes the extra mile to disable certain hooks used by file manager plugins, preventing their usage for removal. This multi-faceted attack underscores the complexity and persistence of modern web-based threats. The credit card skimming aspect of the malware involves injecting an obfuscated JavaScript code, utilizing atob to conceal the location of the malicious script.
The injected script is hosted on a domain, ‘lin-cdn[.]com,’ attempting to mimic the LinkedIN CDN domain to appear legitimate. The skimming code has sophisticated features, including conditions for exfiltrating card details based on the URL containing “checkout” and the absence of the WordPress administrator bar. Moreover, the malware integrates seamlessly into the infected checkout page, utilizing actual image files for credit card logos from the compromised website.
The exfiltration of card details is observed sending them to a remote server controlled by the attackers, emphasizing the common method employed by such attacks. The recent registration of the exfiltration domain, ‘fbplx[.]com,’ suggests a tactic to avoid security vendor blocks, as newer domains are less likely to attract attention. The MageCart malware campaign showcases an evolving threat landscape, adapting tactics within the WordPress ecosystem, particularly leveraging malicious plugins to deliver payloads and gain unauthorized access to sites.
Website owners, especially those operating WooCommerce sites, are urged to secure their wp-admin panels, keep plugins and themes patched, and implement robust security measures to protect against such threats.
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