Security in a network

[Bellzemos]

Hi, I have a question.

If a computer in a MS Windows based peer to peer network (a workgroup which shares files and printers) gets infected by malware, is there a higher chance of it infecting other computers in the workgroup as opposed to the computers not being connected into a workgroup but only sharing the same router and modem for the internet connection?

Is there any other vulnerability except for the obvious - potentially infected files in the shared folder of the infected computer being manually copied to another computer?

Thank you.

[Para-Noid]

Yes! If any set of computers are connected as a work group then the possibility of cross-infection
increases. This is especially true if they share the same server. If you take a file from one machine
in the work group via flash drive to a machine outside the group then the possibility of infecting the
non-group machine increases.

avast provides P2P protection.