kuklorest

Doesn't sound anything like Apple's own. Etrecheck should be able to tell you whom it came from.

It's adware. You most likely installed it along with something else you recently installed.

You can either follow Apple's manual instructions for removing adware, or use the free automated tool, Malwarebytes Anti-Malware for Mac.

It should be noted that Apple's manual removal instructions are typically outdated. Sometimes a lot outdated. It depends on when Apple last updated their instructions page. If you would prefer to manually remove the adware on your system, you can find much more up-to-date instructions on The Safe Mac's adware removal page.

No it was not. See the following previous discussion which may help: what is kuklorest? Something seems to be taking over my browser and setting it to bing