Leo, a third-year CS student, had never heard of LDP.exe. But the pop-up looked legit—official Windows font, a progress bar, and a countdown timer. “Download LDP now to restore system files,” it warned. His thesis was due in six hours.

It was 2 AM when Leo’s screen flickered, then froze. A dialogue box appeared:

He clicked the link. The download was fast. The file was small. But the moment he ran it, his wallpaper vanished. His mouse moved on its own. A terminal opened, typing commands in rapid bursts: net user Hacker /add , net localgroup Administrators Hacker /add .