Unnatural Links to site – impacts links
Unnatural links to your site—impacts links:
https://support.google.com/webmasters/answer/2604772
Some example scenarios that have resulted in this type of action:
https://googlewebmastercentral.blogspot.com/2012/07/new-notifications-about-inbound-links.html
Disavow links help article:
https://support.google.com/webmasters/answer/2648487
Disavow links video:
https://www.youtube.com/watch?v=393nmCYFRtA
Find more webmaster resources at https://www.google.com/webmasters/