Right wing right wing right wing, page-8

You can label it whatever you want, but most people would label it "Islamic terrorism" which is what it would be.

If an avowed communist or extreme environmentalist committed a terrorist act in the name of either of those then you could call it "Left-wing terrorism". Strangely enough though that almost never happens these days (though as the world gets hotter and more polluted due to humanity's influence I would unfortunately not be surprised if we start seeing such acts).