Where is the Weblogic Console login stored and what are the "_IAU" and "_WLS" prefixes for

Trying to understand how weblogic works under the hood. Situation is that a password expired message is showing in our logs, but the only usernames in the schema that the db server admin see that have expired are the "_IAU" and the "_WLS" users. Is this the same as the weblogic console username and password? If not, what are the usernames as they seem to be generic. And also, where is weblogic's console password stored?

Thanks!