You can easily diagnose from where comes the leak :
- Was your computer on when the coins have been sent ? - Do you have an anti-virus software or firewall ? Was it up to date ? - Did you have the same password on your wallet and on any internet website/service ? - Did you enter your password anywhere ?
I don't know if that's relevant.. but my Bittrex BTC address also starts with "1N" coincidence ?
thanks i see the coins
answers to your questions: 1) no i was offlin when coins were sent 2)no i have no antivirus or firewall- im using ubuntu 16.04 3)no password was only used for electrum wallet 4)no Best regards