The exploit has been used to infect WordPress sites with for example redirect scripts, causing the visitor to be redirected to other sites when clicking on internal links in the site. More information about the details of the exploit can be found here.
To solve the problem:
- Make sure WP Live Chat support plugin is updated to version 8.0.29
- In WP backend, go to Live Chat -> Settings -> Custom scripts and remove the unwanted code from the Custom JS box (see image)