Hide Website from Theme Detectors and Hackers
First, follow the instructions to set up the WP Ghost in Safe Mode or Ghost Mode and secure your website.
Here is the tutorial that will help you hide and secure your website:
Hide Your Site From Theme Detectors and Hackers Bots
Website Security Check
After securing the website, you need to check its security. Use Security Check from WP Ghost and third-party security scanning websites to check for all possible vulnerabilities.

Theme Detectors Check
Now, check if the WordPress CMS is hidden from Theme Detectors and Hackers. Use external WordPress detectors that will check for CMS, version, WP paths, plugins, themes, and everything that might lead to the WordPress CMS.
http://whatwpthemeisthat.com/
http://www.wpthemedetector.com/
https://whatcms.org/
https://hidemywpghost.com/#security_check

