I stumbled upon that problem some time ago and this is the best solution - even supported by Kromm - that I found:
http://forums.sjgames.com/showpost.p...33&postcount=9
Basically, you combine Aura (+80%) with Always On (-40%), Melee Attack (-30%) and then slap on your desired Area Effect (+50%/level). Note that this makes for a pretty cheap power by itself if you use multiplicative modifiers. I would decrease the value of Always On for anything that is less dangerous to you than the classical fire aura.
I see no problem with just slapping your desired Malediction level onto that build. You save yourself the trouble of taking a Concentrate manoeuvre instead of Attack, but that's a wash for me.
You can find the same rule stated a bit less clearly under Affliction in Powers p. 39.