This is an old story back from September, 2011, but since recently I’ve seen users complaining about this, I want to share it again [Credit to NakedSecurity, SophoLabs]:

You may have received an automated call from a user who claim to be from Skype or somewhere which says:

Attention: this is an automated computer system alert. Your computer protection service is not active. To activate computer protection, and repair your computer, go to [LINK]

Indeed that’s a scam and visiting the link will lead to getting infected by Fake Antivirus (Scareware), the website claims that you are not properly protected – and it urges you to install its software (a steal at $19.95).

To stop such calls in the future you can set your privacy options to only allow calls from your contacts:

Here is a video that show an example of these calls: