It's using BitDefender ( http://linux.bitdefender.com ) scan engines and virus definitions. And yes, it can be udated from the Live CD using "bd register" command or from Webmin interface.

To use webmin interface, you need to do some tricks (due to special Knoppix configuration). You need to set a password to "knoppix" user and log into webmin with "knoppix" user and the password you set before.

The totally cool feature of this LinuxDefender is the ability to scan and disinfect NTFS partitions from Linux. Altough the instant SMTP proxy antivirus and antispam feature of LinuxDefender is the flag ship of this remastered Knoppix.