I just woke up this morning with the notification of unusual transactions on my imtoken app.  The person transferred $1.28 worth of ETH from my account ($0.62 + transaction fees of $0.66).  The ETH was the one I left in the wallet for gas fees.  I can't remember giving anyone my private key.  I just can't figure it out.  Please I need help if there is anything I can do before the one that will be worse than this happen.

Below is the transaction hash

https://etherscan.io/tx/0x427d1c7cc3f6662ef99831dbafd272047fe39e9e9500cb29d6003f80d4333427