Accidentally if you submit Master Key to claim rewards from weird 3rd party, and when you checked your STEEMIT account today, you might see it was hacked and you already lost everything.
If your account is not yet hacked, just change your Master Key and never use it to claim anything.
Original Source
Did you use your "Master Key" with any other 3rd party tool on STEEM before?
If your account is not yet hacked, just change your Master Key and never use it to claim anything.
Original Source