Brute-Force attacks (also called an Exhaustive Key Search) are used with the intention of gaining access to the server or website by guessing the login authentication. Hackers who use this method typically have several computers with very fast hardware which use an algorithm to guess the password. These machines can guess thousands to millions of passwords per minute, and they will typically guess every possible password. This can be a very dangerous attack if security measures are not set up properly. The best way to prevent a successful Brute-Force attack is to prevent access to the login page after a certain amount of failed login attempts (implemented into most firewalls), to have a strong, secure password, and to set up two factor authentication. Two factor authentication uses a password, and also sends a verification code to the user’s cell phone. This makes it virtually impossible for Brute-Force attacks to be successful.
