If you are totally sure you don't know that address, then it almost seems like you used a malicious client.
Do you remember where you downloaded Electrum? Did you verify the signature of the download?
Have you used mybtgwallet or claimed forked coins lately?

The 2.0551166BTC that got sent to 1BfzVjwQAouUEBNMU4xStTLqMMkbin15kM got immediately forward to 157WDeAU3LvWopxR4hQXnxUzxpcq1LFE4H. Script-sweep like behaviour.