Program the Stealth virus by selecting [Turn on] next to your Personal Computer, and then selecting the Stealth Virus from the list of viruses available for you to code.
In order to be able to code the Stealth Virus, you need to have completed the Expert Programming Course.
You can sell this virus for networth, or use it for it’s corresponding crime.
The Stealth Virus takes 100 Days to code
To see the other viruses that you can code, and some more information, go here.