AdWords disapproved my ads with the message "Malicious or unwanted Software". What should i do?

This error is not related to AdNabu. The error occurs because of malicious scripts present in your website. This could arise because of rogue plugins and other non secure javascript code. You will also get this error in your webmaster tools console as well. 

To identify which scripts cause the issue, you can use a third party scanner like quttera to find rogue scripts.