First, Safari. When Safari users visit icloud.com, if they see a green lock in the address bar and display Apple Inc., click on the green lock, and a message pops up saying "Safari is using Www.icloud.com's encrypted connection." This means you can safely access the page and log in to your account.
If you see the hint "safari can not verify the identity of the page," be careful, do not easily log into your account, or there will be a risk of leaking passwords.
Apple also offers Chrome and Firefox verification methods that are similar to Safari's approach, and no matter which browser you use, the login icloud.com is best to determine whether you have a trusted certificate before you log on to your icloud account.
Since the icloud account is the user's Apple ID, once the icloud account is stolen, it means the Apple ID is stolen and there is a risk of leaking personal privacy.