Now, what I'd like to see would be a government or media-empire with the balls to try something new with ISIS. Fake a high-profile bombing with fictitious Islamic individuals as named culprits and see if ISIS claims credit for it. If they do you can use that information as you see fit, whether publicly exposing the incompetence of ISIS or holding it back for some other purpose if one springs to mind. Since terror-groups rely on their attacks being widely published as they happen or in an exaggerated form, otherwise there is no gain for them. So threaten to completely write the narrative yourself.
Manufacturing and publicizing a fake terrorist attack would just be more fodder for the conspiracy theories a disturbingly large number of moderate muslims already believe. That western media and governments have an agenda to denigrate muslims as a whole and that terrorist attacks in the west are orchestrated towards this goal. Often jews come into it, in one way or another.
And that's ignoring whether that's realistically possible. How long would such a fake story take to debunk, in this day and age? Wag the Dog wasn't a true story, you know. The information age made disinformation and clickbait more prevalent, but the gold is still there buried under all the shit if you dig enough. I would give it a day at most.
And this whole chicken and egg debate about terrorist attacks isn't new, Al Qaeda did the exact same shit. Exhortation of muslims living in the west to violent jihad has been a propaganda tactic of these groups for decades. If the individuals doing it themselves claim links to IS, even if only ideologically, I get why IS would see that as a legitimate claim. Even despite the trappings of an actual government IS remains very decentralized and fluid outside of anywhere except Syria and Iraq. North Africa and elsewhere they remain the same disconnected cells acting independently one of another, except on the largest strategic goals, which IS being an insane theocracy is entirely determined by what the ideology dictates.