Matrix Attack Rating is defined as Attack+Sleaze ... thats not just for Deckers.
No contest here, I just misinterpreted the line in the current CRB version
However: Spiders being able to use host attributes instead of own Matrix Attributes for their own active Matrix tests: I think thatīs a good thing, but I canīt find anything in the written rules that supports this. P. 179 comes closest: "A persona actively defending for a device or host can use the other pool with the device or host attributes." But this reads as if itīs meant for defense tests only - and more precisely, tests where two different pools are available.
And true, most uses of Matrix Attributes are passive. But especially Attack is a bit of an outlier here. Itīs only used in the defense pool of Jack out, meaning it "protects" you (or a host) against the targets getting out of your link-lock. Apart from that, its used to calculate the Attack rating
and the base damage of a the Matrix Spike attack (but no other attack!).
I forget and don't have a book at hand: do any IC use Attack in their defense roll?
The Jammer IC lists "Defense: Willpower + Attack", but thatīs
not the defense pool of the IC, itīs the defense pool if its victim. Attack is used here because the Jammer IC ... erm ... attacks the Attack Attribute

(Itīs the same with the other Attribute-Reducing types of IC, btw. They also worked the same in 5th Edition).
If Iīm not severely mistaken, IC defends itself with whatever pool is determined by the Matrix Action used against it. So, a Tar Baby IC (or the host its running on? Makes no practical difference here) would "defend" with Attack + Data Processing against an enemy hacker it has link-logged if the hacker wants to slip away with a Jack out action.