Is a negative energy attack with Con drain considered a magical attack

[Macgreine]

It doesn't seem like it but I was wondering if a creature immune to magic attacks would be affected by it. Just to clarify its a wraith attacking a wilo-wisp.

[LazarX]

Negative energy drain is not a spell effect subject to spell resistance.

Will o wisps are not immune to magic effects.. only to any effect that allows spell resistance.

Which means most conjuration effects that don't rely on them falling into pits, work just wonderfully.