How to get rid of unwanted pop up

My wordpress site has suddenly (within the last hour) started throwing up multiple pop-up ads on every page, both on the public side aand in the admin area. https://ciderpressreview.com.

A bunch of new posts launched overnight and this morning, but I haven’t added or changed any plugins or widgets in that time.

I tried uploading a clean config.php fiel to see if that cleared it, but it does not. Any suggestions? Please help if you can.