He opened Task Manager.
Process: svchost.exe (but there were five of them, and three had no digital signature).
Leo sighed and closed the window. He went to bed. Three days later, his roommate, Mia, asked, “Hey, did you buy something from Amazon? I saw a package confirmation email in the shared account.”
He logged into his email. It was fine. He checked his bank app: $0 balance.
Leo learned that the hard way. His PC never trusted an unsigned executable again. And he still doesn’t have Wi-Fi.