Spam pop up tabs

Hi Im hoping someone can help me. I have had my new laptop for about a month.
The last few weeks on the same window - the one with my AT&T Yahoo home page,
I keep getting spam opening up in a new tabs. I have cleared all cashe,
cookies, temp files and history. I have also ran the windows defender. I have
McAfee Security running. Nothing help. Please help

Any suggestions are greatly appreciated.

Thank you