I usually just ignore the fact that I have wormguard 4.0 installed. I assume that it is working. However, I do wonder now and then and do not know enough about worms to understand why there is no need for frequent updates when my virius scan software is constantly being updated. If I understood this it would help me to feel secure and happy about not having to pay attention to it.
From http://wormguard.diamondcs.com.au/ "It uses generic, heuristic detection of worms - WormGuard tries to figure out what a file is capable of. WormGuard then calculates the risks based on rulesets developed through worm research, and gives you an alert if there is anything possibly harmful." I highlighted the parts that should answer your question. The program does not rely on definitions, but on heuristics. Heuristics can be finetuned, but don´t need updates like a program depending on definitions would. Regards, Pieter