getting rid of adware and spyware

Remove Adware and Pop-ups

The Safe Mac » Adware Removal Guide

AdwareMedic

Remove unwanted adware that displays pop-up ads and graphics on your Mac - Apple Support

Adware

1. Use free AdwareMedic to remove adware

http://www.adwaremedic.com/index.php

Install , open, and run it by clicking “Scan for Adware” button to remove adware.

Once done, quit AdwareMedic.

or

Remove the adware manually by following the “HowTo” from Apple.

http://support.apple.com/en-us/HT203987

2. Safari > Preferences > Extensions

Turn those off and relaunch Safari.

Turn those on one by one and test.

Malware

http://www.thesafemac.com/mmg/

Best.

You can start with some suggestions here

Remove unwanted adware that displays pop-up ads and graphics on your Mac - Apple Support

Another option is to install a third party piece of software

New Safari with Yosemite opening annoying ad pages

but that is not necessarily needed.

The two schools of thought demonstrated on some threads

Safari out of control in yosemite

Safari won't start after upgrading to Yosemite

Hello, Do you find it necessary to run a removal adware/spyware/trojan or any others more than once? Do I need to run an additional virus protection to check for other malware/trojan/spyware etc infections or will this one you have suggested do it all for me??

I had a pop up box announcing "You have been infected with adware/spyware: Contact frontier now before you buy anything online..." I contacted my internet company this morning and they didn't know what I was talking about--So, Obviously I came back to Apple Support... Thanks you again. gramaL

What you loaded was a scam page. If the pop-up reloads, force quit Safari (command - option/alt - esc) and reopen with the shift key held down. If that doesn't work, disconnect from the Internet, go to Safari/History and delete the website. Quit and reopen with the shift key held down.