How do we know if a website is not secure?

Examine what is written on some sites to find out if the web comment is fake:

Address protection security certificate: On a fake website, leaving the address protection certificate or having a wrong certificate can be a sign.
URL address: A fake website, the URL address may be different from the real web comment URL or be used in a similar way to the real website.
Content: On a fake website, the content is not available on the real website or uses false information.
Design: A fake website, the design may be different or inferior to the real website.
Pop-ups: A fake website may attempt to redirect multiple pop-ups or provide false information.
Information from a reliable source: It is necessary to check with a reliable source (eg google,virustotal) to find out if it is a fake website.

However, these factors do not always guarantee to detect a fake web data. If you are worried about sharing your user information or personal information, please be careful and only receive information that is reliably protected.