The search engines want their users to have a positive experience. They are not going to send their users to a website that gives the user a negative experience. This means that if your website does get infected with malware or try’s to install scripts on a visitor’s computer, the search engines are going to take action to either remove the website from the search results or put a warning in place about the site. Either way, the outcome for your site is not a good one.
We do not expect this to happen with our clients sites as we make updates to the core files and plugins as soon as they are available to patch vulnerabilities and we constantly screen for anything suspicious such as malware.
However, we do monitor the various search engines for the blacklisting of our clients websites. If they do get blacklisted we take immediate action to clean the site and get the blacklisting removed.