I suppose that's a possibility. They hack an account, send the items from my character to their mule, then sell those on the RMAH.
Here's the problem though; Blizzard would be able to shut that down easily, and fast. Selling something for actual cashmoneys won't be as easy or fast as selling a stack of stolen Truegolds, or handful of Essence of Destruction, and then they'd have to withdraw through paypal on top of all that, and that money could be EASILY blocked.
I have a feeling it won't be worth the effort to hackers.
They can just launder the money through a bunch of AH transactions, both cash and non-cash. They'll figure out a way. More fundamentally, how are they going to reverse the trades? If I steal your Sword of Awesome and sell it to random person X for real money, are they going to give you another sword (with real money value) while letting person X keep his? Are they going to take away person X's weapon and refund him (while I have already cashed out the money)?
I have a feeling it will be the jackpot for hackers, unless Blizzard does the responsible thing and includes an authenticator in every purchase.I have a feeling it won't be worth the effort to hackers.
Well, although stuff you would spend real-money on might not sell as fast it's still going to sell. I think a good way to avoid that would be, for example, having the money transferred to PayPal with a delay of several days. That way you get hacked and your items get stolen, sold on the AH they'll have a chance to react. That, however, is a problem in and out of itself.
When person A gets hacked by person B and person B proceeds to sell said stolen items on RMAH and person Y buys them they'll have to take the items back and refund their money which is just proper bollox if you ask me. I imagine that will leave a heckuva lot of unhappy players.