An attacker is trying to redirect the traffic of a small office.

An attacker is trying to redirect the traffic of a small office. That office is using their own mail server, DNS server and NTP server because of the importance of their job. The attacker gain access to the DNS server and redirect the direction www.google.com to his own IP address. Now when the employees of the office want to

go to Google they are being redirected to the attacker machine. What is the name of this kind of attack?