This document provides a link to information that can help you identify the computers on your network that are infected with W32.Blaster.Worm, its variants, W32.Welchia.Worm, and other RPC worms.
Symantec Security Response has profiles of W32.Blaster.Worm and W32.Welchia.Worm activity that can help you find and eradicate this family of malicious code from your network. The profile may also be used to identify other RPC worm infections. For specific information, read
Detecting network traffic that may be due to RPC worms.