I've just opened my Multibit wallet on my MAC after several days and I've noticed my account was cleared. The client was off during all this time and the wallet was password protected. How is this possible at all? Is there anything that can be done at all?

This is the address were the bitcoins were transferred https://blockchain.info/address/1N7SEpAux2LMtReebJQazkPX8oSXxZx2qf

... and when I opened my Multibit Wallet I found this address inside the send box adress, like someone just input it??

Anyone that could help?