Once there was a p2p based worm it wasn't harmful but self-propagating. Essentially it listens on the p2p network port for query messages and then generates a copy of itself as query results come in. Users who download and run or view these files become infected with the virus. Which uses the host machine to spread itself.

There's more detailed information out there on this problem and you find threads dedicated to this topic.

Unfortunately I cannot recall where.


Hope this helps.


http://www.leeware.com