Someone more expert than me could help... I am not a pro, just doing research on a website... Google Search Console shows many backlinks in pages under unknown domains... this pages are mirroring the pages of the linked website... clicking on a link on the mirror page leads to a spam page with link spam... The homepage of these unknown domain appear just fine... looks like that the domain is partially hijacked... WTF?! Have you ever seen something likes this? Can it be an outcome of a previous blackhat activity?