Wow... that's a freaking theft... The wallet was online I assume?
Electrum - dropbox was compromised (with plain txt for the pwd, I know I know..)
plain txt .... and on dropbox ...
I am sorry to hear this but good luck buddy !
It looks like that you only had the coins at the address for two days.
Do you think it would be possible that you accidentally marked the file as public so anyone with the link could access it?