Certain Critical for an ability/attack

[Testin]

Simply click Malorne at Sanctuary of Malorne in Mount Hyjal and you get the following 3min buff (ID 101376)

Buff name: Presence of Malorne
Effect: The spirit of Malorne is with you. Your next spell, ability, or attack that is capable of critically hitting will be a critical hit.
Usage: Many fun uses, for example a guild can use it for some extra dps boost upon pool

Note: Appears at his sanctuary after you complete Between the Trees (untill the next daily reset)

[Parog]

Not an exploit.