STUXNET, DUQU, TILDED and FLAME did not target Iranian banks, but rather Iran's illegal nuclear enrichment program (which contravenes the terms of the Nuclear Non-Proliferation Treaty to which Iran is a signatory).
If Israel and the United States were to decide to descend to the level of Iran, rest assured that Iran's electrical grid, oil production facilities and banks would be trashed in a matter of hours, probably beyond the point of rehabilitation. Iran would effectively be crippled.
Hey -- not a bad idea, actually .... hope Iran likes some really, REALLY bitter medicine.
Iran's attempt at revenge will be met with retribution. There is a difference, which appears to be lost upon you, despite the fact that it is not a subtle distinction.