S: Let’s back up a second. Why did you write adware? M: I was utterly and grindingly broke for a little while. I started working on SPAM filtering software. That work got noticed by [Direct Revenue], who hired me to analyze their distribution chain. For a little while, the site through which all their ads ran was something like top 20 in Alexa. Monstrous, really huge traffic. Maybe 4 or 5 months into my tenure there, a virus came out that was disabling some of the machines that we had adware on. I said, “I know enough C that I could kick the virus off the machines,” and I did. They said “Wow, that was really cool. Why don’t you do that again?” Then I started kicking off other viruses, and they said, “That’s pretty cool that you kicked all the viruses off. Why don’t you kick the competitors off, too?” http://philosecurity.org/2009/01/12/interview-with-an-adware-author