WordPress Sucks,
One of our site was affected with Jquery.min.php malware. Don’t want to explain more. It just injects a jquery script in the header of your website and alter the last modified date of the affected file so you could not guess which file was affected if you were looking for recent file modified date.
If you load your website directly from your browser, you can view the site without a problem. But if you go to your site searching from google, yahoo or other search engines then your site will be redirected to scam website.
How to fix.
In our case, it was the header.php file of the current theme that was infected. Just open the header.php file through your control panel or FTP and look for suspicous script that links to jquery.min.php from the malware server.
Just Remove that script and you are good to go. This will only fix the issue, Use a plugin like sucuri scanner
https://en-ca.wordpress.org/plugins/sucuri-scanner/
And scan your wordpress website. Remove any infected file.
Make sure you backup before doing this.