Thousands of WordPress Websites Infected with Malware

The malware includes four separate backdoors:

Creating four backdoors facilitates the attackers having multiple points of re-entry should one be detected and removed. A unique case we haven’t seen before. Which introduces another type of attack made possibly by abusing websites that don’t monitor 3rd party dependencies in the browser of their users.

The four backdoors:

The functions of the four backdoors are explained below:

  • Backdoor 1, which uploads and installs a fake plugin named “Ultra SEO Processor,” which is then used to execute attacker-issued commands
  • Backdoor 2, which injects malicious JavaScript into wp-config.php
  • Backdoor 3, which adds an attacker-controlled SSH key to the ~/.ssh/authorized_keys file so as to allow persistent remote access to the machine
  • Backdoor 4, which is designed to execute remote commands and fetches another payload from gsocket[.]io to likely open a reverse shell.