The great influence of isis changed the world's view of Islam which is a beautiful religion. Good or bad human behavior is not seen from religion.
The ISIS is a recent phenomenon. They became famous only 4-5 years back. Even before that the Islamist terrorism was known all over the world, in the form of groups such as the Taliban (1979 onward) and Al Qaeda. Even groups such as Boko Haram and Abu Sayyaf are more experienced than the ISIS. But what differentiates ISIS from the rest is their brutality and ruthlessness.