How safe are plain text passwords on a computer?

[radderfire]

How safe would a plain text password in a Word Doc or similar be on your computer against being found by an external hacker? If you have a standard modem/router setup, how vulnerable do you think a computer is? I am careful about what I download to the computer, I don't open dodgy file attachments etc, but I do use Open Source Apps.

Thanks for any thoughts.

Rgds

 

[radderfire]

I have the standard Windows Firewall on.

Rgds