Hello everybody,
I wonder if anyone has ever met a case like me:

Last night (14/12/2017) I transfered 10 Ether from the Exchange to my etherwallet . The ether would be locked on the exchange for a while before the transaction  was executed so I turned off the computer an went to bed.
This morning (15/12) I woke up and found my wallet still at zero while the ether on the Exchange has disappeared.
Thus I checked the https://etherscan.io  , I found that my transaction had been sucessful, 10 ETH was moved to my address smoothly.
But right after 4 minutes another transaction was sucessfully executed , which moved all my ether from my address to another one 0xb4c167ce26a3adfba6abd08d714403f436c75e54   ( I completely don't know this address) , and of course my wallet is zero forever now.

Everything happened in my sleep.

The problem is I don't know what really happened here.
I created a new wallet before I executed the transaction, and I did the transaction at home, very careful with the warning from the service and prudent with my password or my key---> I don't think my computer got hacked or my password stolen since I created a brandnew one and never clicked on any links either.

Then how the heck my Ether got moved from my wallet right after it moved in?  
Is there a chance toget my Ether back ?? ><

I sent a message to myetherwallet support but I doubt if I ever get the answer.