Website showing malware warning – need urgent security fix

My website is currently showing a “Dangerous site / harmful software” warning when people try to visit it.

Browsers are blocking access and saying the site may contain harmful content or malware.

I need an experienced website security specialist to:
Identify why the website is being flagged
Remove any malware or malicious code
Check all files and database for infections
Check plugins, themes, scripts and hosting issues
Secure the website properly to prevent future attacks
Help remove the warning from Google Safe Browsing
Ensure the site is safe and accessible again

Important:
This needs someone experienced with website security (not basic web design)
Please explain what caused the issue and what you fixed
Please confirm what protection you will put in place



Ideal experience:
Website malware removal
Website security hardening
Google blacklist removal
WordPress security (if applicable)

Timeline:
I would like this fixed as soon as possible.