Computer is disabled. Please call me

My dad sent me this photo of his laptop this morning: https://ibb.co/1QRKqsg ... It's a full screen window with all kinds of fun looking popups suggesting some kind of ransomware. I assumed the worst.

He'd clicked on a large "clickbaity" sponsored ad in his Facebook feed about measuring the length of your fingers. He wanted to know if he should call the number on the scam (it lists an Australian toll-free number).

Turns out it was just a pretty website .. a great excuse to reintroduce the basics of online security / awareness to an uninterested audience.

I understand how this stuff might get through some basic ad link checking setup, but serious question .. this is a stupidly low-tech scam. How does it end up in the main Facebook feed, almost working?