What is SEO Spam?
SEO spam is what attackers will inject into a website to attempt to use your SEO ranking for something else not ranked otherwise that will further the attackers’ objective. They spam and destroy the website while trying to generate revenue or achieve some other goal.
Due to this, generally, the website owner is completely unaware of what’s going on unless they receive warnings or are added to blocklists.
Usually, a hacker will try to avoid being detected by rearranging links that aren’t visible to the average site visitor and only crawlers/index engines can see it.