I suggest immediately running your anti-virus/malware/spyware software using updated virus signature files, while you are not signed on to Skype. Obviously, it could be coincidence that another update was being downloaded at the time the spam call arrived.
One of my favorites is SpyBot Search & Destroy which allows you to set a restore point.
When you sign back on to Skype, and going forward, please Block and Report as Abuse all such incidents of these calls/contact invitations as they alert Skype to the newest mutation of a known scamming/phishing attempt.
