Actually there are about 25,000-35,000 Persian Jews living in Iran, most live in Tehran. There are several synagogues in Tehran, Yusef Abad one of the most prominent.
Certainly possible for the Mossad to recruit a handful to assist with covert activities, though if I had to bet on it, I'd say the guys doing the most risky part of these jobs, the guys on the bikes planting the bombs, are probably just anti-regime Iranians wanting to do something to damage the regime's most precious nuclear program that maybe don't even realise that their operators are the Mossad.