This flowchart shows the stages of a worm attack. There are four overall stages, which are broken down into more detailed steps. Before the first stage, the first step indicates that the process is started by a worm / native computer. The first stage then contains these steps: Probe network; Probe other computers; Identify vulnerable computers. The second stage contains these steps: Penetrate & open network connection; Execute instructions remotely. The third stage contains one step: Download a copy of itself. The fourth stage contains the steps: Begin executing; Probe network. There is one more step after these stages which is simply: Propagate further.