To find the hidden links is the primary task of any project for which third-party templates of cms-systems and any other html-templates are used.
From the point of view of search engine optimization the presence of external hidden links in the site template not only negatively affects the development of your project but also favorably affects the site that is listed in these links.
Third-party links that can be listed in your templates can significantly lower your site in the search results of search engines. And the sites with hidden links fall under the sanction of search engines with a bigger probability.
The more external links there is to a site the better for determining the ranking of a site in the search engines. This is one of the main reasons for placing hidden links in templates of popular cms-systems.