If it's a free first please post the java code or you can look over it yourself look to see if it has any lines that involve any url links or email addresses things in that nature sending passwords to a certain place.
It's not asking for you username and pass.
This Script required a username and pass from the owner of the script.
The Owner of the script is Hunter bdb and he posted this script for beta testing ( so to speak ) and now he made a real flawless version that costs $5.
Then again this script required username and pass from hunter himself, He already made a thread on this just look through forums.
its NOT asking for your username and pass
It seems to me that it's asking for some sort of an authorization for the use of the script itself, rather than your RS password (or was that even what you thought?)
Yeah I just checked Hunter's Thread and He got mad that people tried to sell his Old Beta Script so he took it down as well as the authorization username and Pass.
This script is useless without his approval,
Go Buy his Script, it's only $5