I use Windows Defender as my anti virus software and do not have MalwareBytes. When I updated my CCleaner (which I've been using for years, thank you), it installed Avast! on my computer without any notice, delayed or otherwise. I would have opted out had I been given a notice, because I like to choose what gets put on my computer. This is the second time CCleaner has done this. I do hope you've fixed the problem because I'd hate to ditch a good program for bad business practices.