Background:
Scrub
When making a *ranged* attack into or through a scrub space, every scrub space that line of sight is traced through adds two range to the total distance instead of one. *Melee* attacks are not affected by scrub.

Confusion can (and does) arise because 'Range' has two uses in the rules - an attack type and a 'distance'. 'ranged attack' would seem to be clear.
However, strangely, Melee is given an explicit exemption which it does not need (already explicitly ignoring range(distance) entirely) and Magic (which has a range(distance) component and therefore does need an clarifying exemption) is not.
If the 'range' term indicated attack type then Magic would be more usefully exempted. If the 'range' term indicated 'attacks with a range(distance)' (ie both Magic and Ranged attacks) then the Melee exemption makes more sense.

Question:
Q. Do Magic attacks ignore Scrub effects?
A1. Yes. Only Ranged attacks are affected by Scrub. Magic and Melee attacks are not affected.
A2. No. Any attack which has a range component are affected by Scrub. That means both Magic and Ranged attacks are affected, while Melee attacks are not.

What about "special" attacks like Word of Vaal? Personally I would lump it in with AoEs and other "template" attacks and, given my sometimes tenuous understanding of the rules, I would assume such effects are not affected by scrub. However, I'm sure others will ask, sooner or later.

The template attacks ignore range anyways, so I think it doesn't matter. and the word of Vaal could be a similar thing because it affects spaces that are adjacent to each other.