online scanners such as trend micros housecall and symantec or pandas might be able to detect rootkits. this would need to be confirmed.
can we update malwarebytes without attaching it to a network / internet connection?
edit - itil is a best practices framework that may help you form good processes
ITIL Knowledge Accelerator: Improving IT Services with ITIL Best Practices and Policies
here is a link to download the definitions alone, but they say that these offline definitions aren't updated daily like they are when you update through the update tab. they may help should your internet connection be compromised by an infection or you if can't access the internet for some other reason though.
thank you for the link, by the description at the top of the page alone, i'm really interested. i'll be doing some reading now...