They might be trying to create toxic back links to their domains and if those domains 301 to your domain, I believe this can negatively impact the SEO of your domain (from what I read). If so you can try to disavow them https://support.google.com/webmasters/answer/2648487?hl=en
They might be trying to create toxic back links to their domains and if those domains 301 to your domain, I believe this can negatively impact the SEO of your domain (from what I read). If so you can try to disavow them https://support.google.com/webmasters/answer/2648487?hl=en