Firewalls, antivirus programs, and other security measures protect our systems and data from unauthorized access. Unfortunately, there is still a means to access the data that requires no technical exploits. Humans being kind or open to manipulation can allow social engineers to get the information they want. By using the credentials of somebody that should have access they are able to bypass the authentication system if they can just convince somebody to give them their user name and password.
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(Credit: Veracode)