Google marks a website with this warning if they find any suspicious code that could be a malware or trojan. Sometimes the reason for this is that your website is hacked and is now used to distribute malicious code.
Another common reason for this error is showing ads from low quality advertising networks. These networks may sometime display ads linking to websites distributing malicious code. [Fix site ahead contains harmful programs error in WordPress]
Before mentioning the facts about fixing this harmful scripts and programming issues.
CAUTION: This is a severe risk to the website as it can crash, damage and destroys all the coding like theme, scripts, plugin and other database structures as related to this website. More so we employ you totally avoid coping, duplicating or phishing any website and loading it into the WordPress database and other related CMS programmes interface.
ADVICE: Kindly contact your host for more solutions.