Same here. I'm not sure of my password and it doesn't even try to login because of the same error as your picture. I also don't seem to know my secret question... So yeah, useless piece of software.
edit: seem to be able to login at the website... But steam sucks so much they don't allow to do anything there.
They've got access to the whole steam database including game accounts and cards linked to them but only compromised the forums. That's what steam keeps saying.
You should deffo change your passwords everywhere and hope for the best.