I just have to share this with anyone that wants to listen ...... I have been hacked for 4.5 million digibyte

I have absolutely no idea what has happened, but yesterday I did a sync of my digibyte core wallet installed on my computer, and when the sync was over, my wallet was empty.
I checked my wallet address DMHUZWvzfJwdiiivnbfkMW34LBmAt5r9Zv in the blockchain explorer and to my horror I realized that the transactions in fact had taken place.
What has happened? I have never given my private keys to anyone, my pc shows no sign og beeing hacked, its fully updated, have the newest antivirus. My wallet is also protected by a strong password. My pc wasn't online at the time of the transactions. Im a sysadmin and i know a thing or 2 about pc security,
How can this happen? can anyone help me to clarify what has happened before i jump screeaming out of the nearest window
