SoftwareHandler is a Mac adware that will attempt to commandeer your browser search and homepage, filling up your desktop with unwanted ads, banners, sponsored links or push notifications. Aside from slowing down your Mac’s browsing speed, when clicked, these advertisements will send you to malicious websites to get money from you or infect your computer further. It may also prevent you from changing your settings back.
SoftwareHandler is usually installed through bundled software without you knowing. You have to remove it immediately before it will further damage your computer.