EZPZ Backup seems to have changed my db password

After installing this plugin, I set the options. When I attempted to BACKUP NOW I was no longer able to connect to my database. This after what seemed like several failed attempts to get backup now to respond.

I changed my user and password for the database, set a new password (updated wp-config). Now things work, but I have deleted the plugin and deleted the original database user because I don’t know why it was hijacked.