Does a Dread Weapon penalize attacks on a critical?

Question

Dread Weapon:

Property On a critical hit the target takes the weapon’s enhancement bonus as a penalty to defenses and checks until the end of your next turn.

Is an attack a "check" for purposes of this penalty?

Answer 1

It seems yes because of attacks are (as you already figured) checks.

From the Rules Compendium, page 22 and 23.

Does a sword swing hurt the dragon or just bounce off its iron-hard scales? Will the ogre believe an outrageous bluff, or can a character swim across a raging river?
[...]
This simple rule governs most Dungeons & Dragons play. Three types of come up in most session of the game: attack rolls, skill checks and ability checks.
[...]

And again, at page 24.

An attack roll is a kind of check that occurs in every battle, where the target number for the check is the defense of a target.
[...]

Note that, conversely, saving throws are not checks (in 4th edition). They are a simple d20 roll that is succeeded on 10 or more. They don't get modifiers from level or ability bonuses.