There are several items you can manage in your Safari browser; extensions, add-ons
and other settings that can help keep your browsing experience & Mac safer. Some
of the ones that give people some grief are associated with unwanted adware, malware
and other items that may become attached to your browser while online.
Install and manage Safari extensions on your Mac. ... were installed from the Safari
Extensions Gallery with Safari 9 in OS X ... Uninstall button ...
support.apple.com/en-us/HT203051
The above is a support article about how to manage extensions. If you have some that
happen to affect your browser that were not added or turned on by your choice, you may
choose to remove or uninstall them. Some of browser dysfunction that may appear to be
a virus or other item could be the result of several additions to your Mac OS X (or iOS)
those may require additional steps that may not be covered in the above article. This is
not to say that other software would be required; no anti-virus would help.
Adware Removal Guide : Identification ... Safari - choose Preferences from the Safari
menu, then click the Extensions ... MacPriceCut, SaveOnMac, Mac Global ...
thesafemac.com/arg-identification/
You could see what additions are still in effect, after shutting down Safari and then restart
it with extensions-off; then clear browsing history. Some items stay in the browser until
you clear those other possible items.
Why do you need to know what happens when Safari Extensions are uninstalled?
That may reveal circumstances which may lead to additional helpful replies.
Good luck! 🙂