Logging in ways macbook pro

[thesheephair]

Hi im running mac os x 10.4 8
Now when im doing work and want to walk away from the laptop i usually start the screensaver so that my password is required to log back on so if anyone did try and go on my laptop a password would be required.
Now my brother managed to find a way of logging onto my laptop even thhough i had the screensaver on , i am 100% sure he doesnt know what my password is , how could he log on without even knowing my password at the log in screen?
I have one account on this laptop and it is the admin. Is it possible that he could install something that would give him my password or something like that ?
Im very curious on how he "hacked" my account

 

[mad jew]

Could he have changed the password? It's possible to change the admin password using OSX install discs. Also, if he restarted it, is your account set to automatically log in? That may have bypassed the password.

 

[thesheephair]

Could he have changed the password? It's possible to change the admin password using OSX install discs. Also, if he restarted it, is your account set to automatically log in? That may have bypassed the password.

No he doesnt have access to discs and no he hasnt restarted the laptop

 

[mad jew]

They don't have to be your discs. They just have to be OSX discs that'll boot your machine.