This is question best handled by your GM, since it could be situation dependent. For example, a healing spell could be considered an attack if used to heal a minimal amount (to prevent further healing) or to stabilize someone in order to cause future harm (those naughty corps, or players, who ignore concepts like minimal standards for prisoner treatment).
I'd say every one of those could be considered an attack spell, but hey, maybe someone wants to light their smokes with a Flamethrower spell. That could be stylish (and possibly stupid) and not an attack... or it could be an attack as well (maybe it was part of an attempt to intimidate).