Well, if you have a computer, I'm pretty sure you'll be able to figure it out on your own.
All coding by me. I'm pretty sure this is the most user-interactive OS on scratch. Go to @EndlessErrors for the more developed version (it's my main account). If you make a virus in your app, please put code in it that changes the "virus" variable (that's already implemented into the OS code) by 1. That's so if anyone makes a anti-virus the anti-virus can detect the virus. You can also make fake anti-viruses that have viruses in them if you want, I don't care.