It’s Chitka not Chikita, see this: http://deletemalware.blogspot.com/2013/03/remove-chitka-pop-up-ads-removal.html
Chitka ads are usually caused by malicious web browser extensions (Flash Player Update 11 and similar) , so you should either remove them or reset your web browser.
Then run RogueKiller http://www.sur-la-toile.com/RogueKiller/RogueKiller.exe
Cheers!