Why did malware hit my website?

Last year I paid someone to re-create a website for me. The person used Word-Press to make the site and siteground to host the domain (not real sure on that terminology).

Recently there was malware that was somehow put onto the site. Google doesn't allow people to go to the site because it considers it a dangerous site.

Does a site made through WordPress more prone to malware such as this? The guy who made the site is now asking for a couple hundred bucks to take the malware off.

I am wondering if I should not use word press anymore due to security issues. Would another option be more secure? Is wordpress more susceptible to this?

Is there anything else I can do to protect this from happening in the future?

Thanks! Any advice would be great.