Bitcoins send out after syncing wallet Good day,

can someone maybe help me.
I just opened my wallet today after I exported it to a private key and incrypted it (Multibit wallet) and more than half of my coins has been send out to an address I dnt know. According to what I can see in the transaction History of this transfer it has been used as transaction fees for someone els`s transfer of coins.
Can this be a problem on the blockchain side or was my wallet hacked.
Any help will be greatly appreciated.

Thank you
Assuming you are checking the balance using MultiBit perhaps your missing coins are sitting in a change address - when you send bitcoin often some coins are moved to a newly generated change address, so you would need to export more than just the one address.

Fire up bitcoincore again and check the other receive addresses in a blockchain explorer for balances.