"I have your lottery winnings. Send (amount) to me to process sending you the money."
That's a scam, right?
"I have encrypted your files. Send (amount) and I'll decrypt them for you."
Not a scam?
That's a scam, right?
"I have encrypted your files. Send (amount) and I'll decrypt them for you."
Not a scam?
Encryption viruses are probably some of the best QA'ed code in the world.