Apple security? Attention!! Virus detected

After Loading the 5-O Browser app (from the App store) , I got this screen that popped up.

I've never seen or heard of anything like this. Is it legit?

BTW iOS 11.01 iPhone 6 plus

APPLE SECURITY

Attention!!

(6) Virus detected on your iPhone! (in red text)

IP address: 00.000.000.00 (these are not the actual ones posted)

One of the last sites you've visited contained a Trojan, loading via the vulnerabilities of the browser.

Click ok to start the cleaning process.

After clean up, make sure to upgrade your system to the latest version.

Install Cancel (in blue text)