Urgent Security Advisory: WordPress Popup Builder Exploitation – Take Immediate Action

Hackers are exploiting a vulnerability (CVE-2023-6000) in outdated versions of the Popup Builder plugin for WordPress, infecting over 3,300 websites. This cross-site scripting (XSS) flaw affects Popup Builder versions 4.2.3 and older, initially disclosed in November 2023. Despite a prior Balada Injector campaign affecting 6,700 websites, a new surge has been observed in the past three weeks, indicating delayed patching by site administrators.

The attacks target the ‘wp_postmeta’ database table, infecting Custom JavaScript or Custom CSS sections in the WordPress admin interface. The injected code serves as event handlers for Popup Builder plugin actions, leading to various outcomes, including redirecting visitors to phishing pages and malware distribution sites.

Sucuri reports 3,329 WordPress sites affected, with 1,170 infections detected by its scanners. Malicious domains include “ttincoming.traveltraffic[.]cc” and “host.cloudsonicwave[.]com,” recommended for blocking.

To defend against these attacks:

1. Upgrade Popup Builder to the latest version (4.2.7), addressing CVE-2023-6000 and other security issues.
2. Block domains “ttincoming.traveltraffic[.]cc” and “host.cloudsonicwave[.]com.”
3. For infected sites, remove malicious entries from Popup Builder’s custom sections and scan for hidden backdoors to prevent reinfection.

Considering that over 80,000 active sites still use Popup Builder 4.1 and older, prompt action is crucial to mitigate the risk of further exploitation.