Why would he do that? Why not send it out from your wallet from your computer?
How would he have your private key and not have control of your wallet?
Why would he intentionally group it with other scam addresses, thus creating linkability?
Have you determined how this "hacker" had performed this feat yet?
You have a good point here .If the hacker is smart enough to break into your computer and steal the private keys ,I'm sure he'd be smart enough to just send the money to his address instead of importing the keys.I do remember you mentioning ,your wallet is hacked too.