I've been always curious about understanding about how virus carry out their activities. For that reason, I've read a lot of books and articles about different types of viruses and the way they operate in a system. One thing that I have never found anywhere and I am really curious about is this:
For instance, let's say I have successfully developed a virus and I've made it penetrate into a system. At this moment, what is the point, how that specific virus can start up its job. Do they automatically launch themselves without the user being involved ? I mean an event requires to be triggered to fire an action, if the virus is copied in the hard drive, what makes it run and carry out its evil duty ? I mean without being double clicked.
I found that in linux it can be done by writing certain scripts but when it comes to windows, I think the os doesn't have such feature. So I would appreciate you if you satisfy my curiosity.