Well, i don't think the situation is something critical.
Ladder is a separate project, everything it do is reading reports, parsing and uploading to it's separate database.
It's being located on the separate hosting and of course ladder database doens't contain any passwords or any other private info from bnet server.
So you can hack ladder, you can change any values in ladder, but it's not related with bnet server.
Of course if one can take an access to bnet database, that would be a big problem, but it's not so easy to do it.
So i have no reason to suppose bnet database is compomised.
I don't think there's a reason to change passwords or w/e...