The most sophisticated software in history was written by a team of people whose names we do not know.
It’s a computer worm. The worm was written, probably, between 2005 and 2010.
Because the worm is so complex and sophisticated, I can only give the most superficial outline of what it does.
This worm exists first on a USB drive. Someone could just find that USB drive lying around, or get it in the mail, and wonder what was on it. When that USB drive is inserted into a Windows PC, without the user knowing it, that worm will quietly run itself, and copy itself to that PC. It has at least three ways of trying to get itself to run. If one way doesn’t work, it tries another. At least two of these methods to launch itself were completely new then, and both of them used two independent, secret bugs in Windows that no one else knew about, until this worm came along.
... read the whole story at www.quora.com.