Over 1,000 WordPress websites have been infected with a sophisticated attack involving malicious JavaScript code that injects four separate backdoors. This attack was first detected through the cdn.csyndication[.]com domain, and so far, 908 websites have been found referencing this malicious domain. The attackers used this method to create multiple re-entry points, ensuring that even if one backdoor is discovered and removed, the others will remain intact. This approach complicates efforts to fully mitigate the attack, as website administrators struggle to detect and eliminate all the vulnerabilities introduced by the malicious code.
The first backdoor involves the installation of a fake plugin called “Ultra SEO Processor,” which gives attackers the ability to execute arbitrary commands.
The second backdoor injects harmful JavaScript into the wp-config.php file, altering the website’s essential configuration and potentially providing attackers with further control. The third backdoor is even more dangerous, as it involves the insertion of an attacker-controlled SSH key into the machine’s authorized keys, which enables persistent remote access. The final backdoor allows attackers to execute remote commands and fetch additional payloads from other domains, such as gsocket[.]io, which may enable the attackers to establish a reverse shell for further exploitation.
Experts have outlined several strategies to mitigate the impact of these attacks, advising users to remove unauthorized SSH keys and rotate WordPress admin credentials. These measures help prevent unauthorized access to the site and limit the potential for further exploitation. Administrators are also encouraged to monitor system logs for any suspicious activity, which could indicate that one or more backdoors are still active within their systems.
Detecting these threats as early as possible is key to stopping the attackers from continuing to exploit the vulnerabilities and gaining further control over the compromised websites.
Alongside this attack, cybersecurity researchers have also uncovered another widespread malware campaign targeting over 35,000 websites. This attack uses malicious JavaScript to hijack user browsers and redirect them to Chinese-language gambling websites, which further indicates the growing sophistication of such campaigns. The attackers employed several domains to host the JavaScript code, including mlbetjs[.]com and ptfafajs[.]com, which act as payload loaders. In a related finding, researchers also reported a new threat targeting Magento websites, where attackers use advanced fingerprinting techniques to track user activities. This demonstrates a continued trend of exploiting known vulnerabilities in popular platforms to gather valuable user information for malicious purposes.
