How do I remove DNSUnlocker and fast-ads.info adware/malware from my Mac OS X?

Hey Guys, I am a Mac OS X user, running Yosemite. I dont install much application on my mac. Also visit most of the websites from hackernews and other trusted websites. I really don't know how this malware/adware came into my book. Do you guys know how do I remove these from my macbook. I will really appreciate it.