Hacker with nickname AlpHaNiX deface Google, Gmail, Youtube, Yahoo, Apple etc domains of Democratic Republic of Congo. Hacker use strategy so-called DNS cache poisoning.
DNS cache poisoning is a security or data integrity compromise in the Domain Name System (DNS). The compromise occurs when data is introduced into a DNS name server's cache database that did not originate from authoritative DNS sources. It may be a deliberate attempt of a maliciously crafted attack on a name server.
Hacked websites are :
https://apple.cd/
https://yahoo.cd/
https://gmail.cd/
https://google.cd/
https://youtube.cd/
https://linux.cd/
https://samsung.cd/
https://hotmail.cd/
https://microsoft.cd/
[Source]