Sorry to hear you where hacked Marcos, both Hive and Blurt are forks of Steem, so if you did not change your Blurt keys the most likely explanation is that someone recorded your Steem keys and used them on Blurt, make sure you change keys as fast as you can, I have not used Blurt myself so not sure what dapps to use for that, I hope you get an awesome weekend and stay !ALIVE
thanks @flaxz.alive, if I have already changed the passwords what I still do not understand is how the information of so many accounts that were hacked could have been leaked