Erybelfaste.com causes unexpected pop-up ads and push notifications, redirects when the program is added to the machine. The adware tries to trick people into subscribing to these desktop notifications. That is, unfortunately, not difficult and interaction with the content of these websites can count as an agreement for the additional content from this or other sites.
There are additional speed and performance issues that this intruder can cause. When the potentially unwanted program runs in the background of the machine it triggers particular changes on the computer. The adware can ensure persistence by altering startup preferences and settings.