I'm not so sure. There's no definition of "attack" in the REG (that I could find) and afaik only evil cards have the "if attacked" wording which has always meant to me that heroes attack and evil characters defend/block (since good cards use "if blocked" wording).
Is there an official definition of "attack"/"attacked"?
Convert uses this verbiage (italics mine), "If a convert ability creates a Hero blocking in battle or an Evil Character attacking" seeming to indicate that heroes don't normally block and ECs don't normally attack.
All instances of "attack" in the REG are either in reference to attacking heroes or in card titles.