Recently Mac Internet, DNS seems to have been hijacked

Recently, using Safari to browse the Web, found that open some of the page will pop up another page. Think it is a computer for some time not shut down, it may be safari some garbage cache or be installed plug-in or something. But Chrome also has this problem. Finally with the garbage software to clean up a bit, shut down the restart is still the case.

It was a search. DNS is hijacked and the DNS server under connected WiFi is viewed:

218.108.248.245 and 128.108.248.228

Search the two are the number of IP, should be automatically obtained, because I use the net of the number of Chinese.

Finally replaced by:
199.91.73.222 and 178.79.131.110

There was no more pop-up problems.

As far as the previous two DNS servers were hijacked the feeling was exploited by another person, should the server have a vulnerability? Because the ads are some of the foreign, and some ads can not open, should not be the operator intentionally put on?

Impression in the win system, has not yet encountered the problem of DNS hijacking of pop-up windows.

Recently Mac Internet, DNS seems to have been hijacked