Matt has clarified this on Rulesmasters... somewhere...
An attack basically means rolling attack dice, not necessarily causing damage. So yes if you beat stealth but totally miss, it still counts. If you beat stealth, get 4 hits but they are all dodged or intercepted then it still counts. If you beat stealth, get 3 hits but they are all bulkheads, it also counts. It is the rolling of attack dice that grants the bonus. So I guess Comms Disrupters can grant the bonus too :lol: