Deleting Safari Extension?

1) In Safari, click the "Safari" menu > "Preferences" > "Extensions"

2) Select "Ghostery" in the sidebar

3) Click the "Uninstall" button in the left pane

4) Confirm by clicking "Uninstall" button

If you want a trusted replacement for Ghostery, you may want to try the Privacy Badger extension by EFF. I've researched many privacy and security extensions and the EFF's "Privacy Badger" and "HTTPS Everywhere" are top notch extensions that have your privacy best interests in mind.

You may want to add "uBlock" (Safari) or "uBlock Origin" (Chrome). uBlock should get rid of macrepair.com. It's unfortunate, but aggressive advertising has reached a point where it's not only obnoxious but is also a threat to the security of web users. Therefore, ad blockers are now almost a necessity.

One additional layer of security that you may also consider is to sign up for and use "OpenDNS Home" (https://www.opendns.com/home-internet-security/). This service adds configurable DNS filtering for your entire household and automatically blocks domain names that are known to be really bad news. A bit benefit of using OpenDNS is that when you encounter a really obnoxious domain name (e.g. macrepair.com, mackeeper.com, and zeobit.com), you can add them to your blacklist and they will never load again in your entire household.

Layered security is a critically important concept to protect technology and information. By using a Mac you are already in good shape, by using OpenDNS you will have a second layer, and by using HTTPS Everywhere, Privacy Badger, and uBlock, you have added yet another layer.

One word of warning is that with HTTPS Everywhere, Privacy Badger, and uBlock enabled, you may find a few websites that simply do not function correctly (particularly comments for discussion websites). For that reason, learn to use each of the extensions' settings to easily whitelist or better yet temporarily disable blocking for those sites that you absolutely must use but deserve to be blocked nevertheless.