Few Tips:

MEW has been victim of the Phishing site. This site looks just similar to MEW and depending upon the sites where you visit, the emails that you receive all can get you this link and you must be able to differentiate in the original one and fake site.

Usually the original my ether wallet address turns green in the task bar and LLC certificate is shown. Always look for https:// which tells us that its safe link.

Try to log in with the Keystone file and do not try the Private Key. Keep it as secondary option to log in.

Bookmark the original MEW website address and always access the site from that bookmark.

This will be enough for you to get started with security.