Domain Name System Hijacking intercepts legitimate DNS requests from the user and matches them to compromised IP addresses hosted on the attackers servers. The Iranian Cyber army took Twitter by storm, after having successfully managed to redirect domain requests from Twitter to its own hosted IP addresses. DNS hijacking is not a pattern of malicious hackers only. Legitimate ISP providers also engage in the ill-feting activity to suit their own selfish interests, including placing ads or collecting statistics for Big Data Analysis.”]
Source: https://resources.infosecinstitute.com/topic/stop-dns-hijacking/