Petya is the latest ransomware hitting millions of computers around the world. Most infected computers are in the Ukraine, where "patient zero" is believed to be. From there it branched out to Russia, Poland, Italy and Germany. It takes advantage of the same flaws in Windows 10 that WannaCry did. Fortunately, it hasn't really hit the U.S. yet, but we'll see more infections as time goes on. Our CIA intelligence service discovered it and didn't say anything because it could use it to spy on others.