I pray to God that who stole this will go to hell and not live on this world
God doesn't give a flying fuck about blockchain. The hacker is going to get hookers and coke with your money - not going to hell. He is going to Disneyland.
Probably someone stumbled upon the page of your priv-key using some site like dictionry.io ?? Speaking of which, Hey RawDog I remember you running bots to search for priv-keys, how did that go after 4-5 yrs of looking through the site