Name mismatch and certificate errorsIf a hacker poses as your server with a made-up certificate, you'll see this warning. Not only does the name not match, the certificate isn't even from a trusted certifying authority. If you see this kind of error when you've already gone through the certificate installation procedure, you know someone is trying to dupe you. You should click No and not connect to the server. If you attempt to make the connection anyway, you'll reveal enough of your credentials for the hacker to quickly run a dictionary attack to find your password.
Jody Gilbert has been writing and editing technical articles for the past 25 years. She was part of the team that launched TechRepublic and is now senior editor for Tech Pro Research.