How does a Shadow attack and energy drain work?

[paladinguy]

http://www.d20pfsrd.com/bestiary/monster-listings/undead/shadow

First, for its attack, does it just roll 1d20+4 vs the victims Touch AC?

And if it hits, then it does 1d6 of STR damage?

How does the victim heal the STR damage?

This guy seems super nuts and powerful for only CR3/800 XP...

[Chemlak]

Yes.

Yes.

PRD wrote:

Unless otherwise noted, damage to your ability scores is healed at the rate of 1 per day to each ability score that has been damaged. Ability damage can be healed through the use of spells, such as lesser restoration .