So on August 20th, I was able to find some blackcoin on the Bittrix exchange.  I setup my own node on my system, and sent my blackcoin into it, and enabled it for staking.

Last night (at about 2AM), my balance went to 0.00

The ledger shows a transaction log b53f8847cf37de262455e2edfecccfc49dae6efe57b4a55e5853ecba33412c43

All my blackcoin was transferred to another account?

I am uncertain how this could happen or what went wrong. My private key was not shared with anyone, so how did my wallet get accessed and the transfer get accepted ?