Malwarebytes (formerly AdwareMedic) can help you restore your Mac's experience. Malwarebytes scans your Mac for malicious code and removes it. Make your Mac again. Although the app can be used to clean infected devices for free, real-time protection is available with an upgrade to the Premium plan . Pricing information can be found here.
Malwarebytes offers a free version that allows you to scan and clean up your computer if it has been infected. The paid version includes more features, such as real-time protection from viruses, spyware, or malware infections. A personal license costs $39.99 per annum for the premium subscription.