There is a Skype hack that can add to the many malicious third party attacks by allowing others to view users' global and local IP addresses.
In a report by The Verge, we have been informed that the hack utilizes a cracked copy of SkypeKit. SkypeKit is explained on the official site as a means of using Skype without a user display by working with a variety of chip sets, operating systems, and audio/video devices.
By using the cracked copy of SkypeKit, it allows the certificate authentication, that is usually used by Skype to verify the app, to be bypassed, thus bypassing any security in the Add Contact process. The app then receives the IP routing information back, leaving the user vulnerable for attack.
While we may just brush this information off, it is yet another means of being attacked by allowing the computers in use to be pinpointed. Denial of service attacks could be then implemented by these third parties.