/autoupdate
Spybot - Search & Destroy
This command line parameter was, up to Spybot - Search & Destroy version 1.4, used to tell SpybotSD.exe that it should look for updates before doing anything else. While current versions of this executable still support this parameter, it is recommended to directly use SDUpdate.exe for any automated tasks, since it allows you to completely separate updating and scanning.
Updater
Used to automatically search for and download updates when run with this parameter. You'll probably want to combine it with /autoclose.