There is a nasty botnet trolling WordPress sites trying to log in with the default admin user name and using “brute-force” methods to crack the passwords. Our advice to save your wordpress blog from being hacked is to change admin as the login name to something else and use strong passwords.
Matt Mullenweg, the founder of WordPress, advises the same thing on his blog. He also said to turn on the two-step authentication, which prompts you to enter a secret number you get from the Google Authenticator App on your smartphone. To make as secure an environment as you can, ensure that the latest version of WordPress is installed as well.
“Do this and you’ll be ahead of 99% of sites out there and probably never have a problem,” Mullenweg writes to assure 64 million WordPress users.