Google has begun adding warnings to its search result listings indicating if it believes a site has been hacked. In such an instance the words, “This site may be compromised,” will appear under the site details. Users are still free to visit the site, but clicking the warning message will lead to a page explaining what can be done to keep safe. Google is keeping quiet about how it detects hacked sites, but we have to hope it’s not something as simple as the site contents changing in a sudden and dramatic way.”]
Source: https://www.csoonline.com/article/2126477/what-if-google-s-hack-warnings-grab-your-site-.html