EasyHandler is the name of a piece of software for Mac computers that exhibits behaviors typical of advertising-supported apps or adware.
EasyHandler can be found in your Applications folder on your Mac. It offers no useful functionality and its main purpose is to deliver ads to your Mac's browser.
This is normal behavior for adware, which serves as many ads as possible and generated revenue for its operators and makers with each ad delivered.
The issue with this sort of behavior is twofold. On the one hand, a lot of ads will take up system resources and bandwidth. On the other hand, those ads can also be sourced from rogue advertising networks. This means that the ads may refer to potentially unwanted apps, malicious or untrustworthy websites and questionable content.
This sort of behavior is obviously not something you want on your computer and it is usually advisable to uninstall adware when you spot it on your Mac. Thankfully, apps similar to EasyHandler usually have next to no persistence mechanisms and can be uninstalled just like every other app on your Mac, by dragging them to the Trash and then emptying it.