Not that it matters since the miner *is* infected, but where do you see that this is a NH owned address?
The miner won't connect if the address is not owned by NH.
As far as I know you can mine to nicehash 2 ways either with an external address or with an internal one
Not that I still use NH but when I did back then you had to use the bitcoin address THEY give you, not just a bitcoin address, white it's a different addy for everyone and you can even send BTC to it, your mining rewards are not sent to that address but rather are stored in NH database and then you can withdraw them to an "external" address, in fact, you can even use the same nicehash BTC address to mine other coins.
If you google this address instead 3BjMWfED7RJvtBPPikJpweDT6A9xRW952x you will find that many people were infected with a virus that uses this address, I have personally had gears infected with a virus that mines to that NH address, so I know for a fact that mining address made a lot of coins, but if you check on the blockchain it has 0 transactions on it.