Even though the protests were initially peaceful, if you're a foreign government looking to do a regime change in Iran, not capitalizing on these moments makes no sense. They knew sooner or later there'd be civil unrest, that's the whole point of the sanctions, and I believe that's why Mike Pompeo believes wholeheartedly that Mossad is there.

There isn't a source saying "I'm Mossad and I did this", but there's an analysis by the Jerusalem Post on the involvement of Mossad on Iran.