Quick website safety check

I have received a warning from my domain service provider, saying that that are malicious content under my domain.
The website is a simple product introduction website with no more than 10 static pages.
I have temporarily stopped the website under the domain and duplicated a copy of the website to the following link so that it could be used to check the content,
http://84f5d5adc1093tp3-org.tap4api.com/
I suspect that there might be some malicious code in our script or plugins.
I need someone to run a complete check on the website and identify the malicious content and provide suggestions on how to remove them.