The link
Visa Entitlement Verification Online for eVisa Holders says we can get the password if we don't have one , I am not sure whether paper based grantees can access it or not
Below lines are from immi.gov.au
Using VEVO
To use VEVO, you must have a Transaction Reference Number (TRN) or password.
See: Enter VEVO as a Visa holder
If you do not have a TRN or a password, or have forgotten your TRN or password, contact the department to get a new password.
Telephone: 131 881
If you are concerned that someone knows your password, you can change it.
See: Change VEVO password as a Visa holder
If you are seeking to check the progress of a visa or citizenship application, you can check this information using the Query Application Status.
See: Query Application Status