You close your laptop. You walk away. When you come back, the mouse is in a different position. A program you didn't open is running. Your passwords stop working. You might think: "Has my PC been hacked?" It's a terrifying thought. But the truth is, hackers don't always leave obvious traces. Sometimes the signs are quiet β€” a slightly slower system, a network connection you don't recognize, a webcam light that flickers for no reason. The good news? Hackers leave footprints...