Your site may link to malicious illegal or spam sites for an attack block these links with the link blocking tool (backlink disavow link).
Links from illegal, spammy links or poor sites can negatively affect your website’s authority and SEO performance, causing you to lose rankings on Google. Block these links with the Google Disavow link tool.
Note: Be careful when using this tool, do not remove helpful links to your website.
Open the disavow backlink tool for manually blocking spam backlink sites.
The opened page will make you select the Search Console property.
Select the property then the upload button will appear.
The file containing the links to be blocked must be a .txt that meets the following conditions;
Example File:
# Two pages to disavow
http://spam.example.com/stuff/comments.html
http://spam.example.com/stuff/paid-links.html
# One domain to disavow
domain:example2.com
Click on the file upload button on the screen. (That appears in the image above, and upload the file you created here)
You can export the incoming links and domains from the “Links” field on Search Console and block the links you want from the downloaded list with the Google Disavow link tool.
You can track harmful toxic links through third-party SEO tools such as Ahrefs and SEMrush.
Source:
https://support.google.com/webmasters/answer/2648487