Q: how to get rid of lunaticake

Use Malwarebytes Anti-Malware: http://www.adwaremedic.com/index.php 

You can also remove the adware manually using the steps provided by Apple: https://support.apple.com/en-us/HT203987

After that, make sure your default search engine is set to the one you always use. To do so, Open Safari - Preferences - Search.

Go to Safari menu (At the very top right side of your screen next to Apple icon), choose "Quit Safari"

press "Shift" button and while holding this button on your keyboard single click on the Safari icon on your Dock.

Open Safari - Preferences - Privacy - Remove All Website Data.

Also, I believe it would be a good idea to install AdBlock.

First, never use any kind of "anti-virus" or "anti-malware" software on a Mac. That's how you cause problems, not how you solve them.

Is Safari affected?

It is an extension. For Safari, Safari/Preferences/Extensions and delete.

Open Google Chrome and select Preferences from the menu. Next, click on the Extensions link which is located on the left side of the window. Once the list shows up, select Lunaticake and uninstall it from the browser.

Open Mozilla Firefox and select Add-ons from the Tools menu. Find Lunaticake from Extensions and Plugins and delete if it is present.

Once removed, restart the browser.