remove mackeeper

if you are using Safari quit out, then hold down the SHIFT key, then restart Safari with SHIFT held down.

then download malwarebytes and see if you have adware

Malwarebytes | Free Cyber Security & Anti-Malware Software

For futher analysis you may post an Etrecheck report. The link is http://www.etrecheck.com

MacKeeper is one of the most aggressively advertised programs in the entire Mac ecosystem, so seeing ads for MacKeeper is, unfortunately, not an abnormal experience. I tend to avoid sites that have the poor judgement to display MacKeeper ads, but there are so many.

If you're seeing MacKeeper ads on a site where they should not be, and where they never show up on any other device, then that may be an issue.