This is absolutely hacked, no one will arbitrarily transfer to a strange address.
Be careful to protect your private key, if you use MyEtherWallet you have to be careful fishing site, so if the amont is small, I suggest you use imtoken or jaxx better.
Of course, hardware wallet is definitely another good choice.
Finnaly someone whos reading and understanding the topic well. Yeah I have been hacked,..propably a fisher indeed. And yeah I hope to learn from this lesson. And let it be a lesson for us all.
Thanks.