Skype's Take on Vishing (Voice Phishing)
Skype is aware of so-called 'vishing' (or voice phishing) attacks, where a recorded call is made to a person to try and coax them to do something, like share personal information via phone or visit a Web site to download malicious software disguised as security updates. As with any form of communication today, users should be vigilant and responsible at all times and be wary of any suspicious activity. Our advice is similar to answering a call on your mobile from unknown parties that you don't recognize: either don't answer and certainly don't follow any instructions from unknown parties, much as you wouldn't click on or visit unknown URLs or download attachments that seem suspicious.
Skype offers privacy control options to keep users protected from unwanted communications. Windows users should just open Tools -> Options -> Privacy and set your preferences for receiving communications, while Mac users can find these settings under Skype -> Preferences -> Privacy. We recommend that you do not authorize calls from people you do not know.
On the rare chance someone starts bothering you or sends you suspect messages, you should add that user to your Blocked Users list by right clicking on the contact from your call or contact list and choosing "Block This Person." You will then be given the option of reporting abuse by this user. This way, suspicious communications will be better controlled and Skype's automated systems for blocking malicious users are updated to protect the greater Skype community.
Learn more about Skype Security & Privacy.