ed1023 writes "Currently I am teaching a 101 class on computers. It is more of a demystifying the black box type of class. The current topic is computer virus. I am looking for a virus that i can infect the lab computers (only connected to local network no outside network connection) with that would be easy for the students to remove by hand. Can the Slashdot community point me any directions, is there an executable out there what would work ( this scares me), or do I try to write one my self, or is there one that is written that i can compile my self?"