File-sharing Networks or P2P Worms

P2P worms copy themselves into a shared folder, usually located on the local machine. Once the worm has successfully placed a copy of itself under a harmless name in a shared folder, the P2P network takes over: the network informs other users about the new resource and provides the infrastructure to download and execute the infected file.

More complex P2P worms imitate the network protocol of specific file-sharing networks: they respond affirmatively to all requests and offer infected files containing the worm body to all comers.