Users all over the internet are reporting that their accounts are experiencing some weird behavior. Apparently Skype accounts have been getting “spoofed” and Microsoft is recommending that all users change their passwords ASAP. Here is the link to the Skype Forum 

Instead of a hard to remember password, you should use a passphrase. 
For example:  Mycatdoesnotenjoyplayingthebongos!2015.
The first reports were posted in skype / microsoft help forums. Others confirmed that their accounts also sent such messages all by themselves.
“My account sent out the same message OP describes. The message was sent at 2345 UTC on 01-07-2015 to all contacts. As a precaution, I changed my Skype password on a different machine. I also checked whether anything strange was accessing the API, but this did not appear to be the case,” one user explained 3 weeks ago. Source
 Microsoft is fully investigating and the only advice or recommended action right now is to change your password.
So go change your password right now.
Why are you still reading this.
Seriously.