Is this a scam?

[NewsBot]

A week ago I was watching videos on Youtube. Then all of a sudden, a new window on pops up saying its a Microsoft webpage, and that that it has detected a virus and spyware in my computer. It was also asking me for my Microsoft username and password, and was saying that I visited some website that was illegal and I would have to pay a fine or end up in prison, but I never visited any website that was illegal. I assumed it was just a scam, and shut down my computer so it would go away. However, this morning that exact same pop up appeared, saying all the same stuff and asked or my username and password again.

 

My question is, is that pop up actually from Microsoft, or is it just a scam?

 

 

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