Why does Google make my website a "Deceptive Site Ahead"

Question

I have installed a Drupal7 site on Debian 9 with Apache 2.4 and MariaDB 10.

But I am getting a

Deceptive site ahead

warning on Chrome though the Google Webmaster tool shows that no security threats were found...

But Chrome designates the following types of URLs as phishing:

/sites/all/modules/views/css/views.css?pexgy1
/sites/all/themes/theme/media.css?pexgy1

Has anybody any idea what could be wrong?