It has been reported a major increase of social engineering attacks on Skype and other instant messaging applications over the last few weeks.

Skype is generally used by users to communicate with peers by voice, video, and instant messaging over the Internet. Phone calls may be placed to recipients on the traditional telephone networks. Calls to other users within the Skype service are free of charge, while calls to land-line telephones and mobile phones are charged via a debit-based user account system. Skype has also become popular for its additional features, including file transfer, and videoconferencing.

Skype has millions of registered users which uses the facilities provided by it. These social Engineering attacks are an issue of major concern as they pose a threat to the security of millions of users.

The attack used by cyber criminals uses the common social engineering tactic of posting a link to instant messaging applications for a potential victim to follow. If victim click the link posted by some cracker, his system is compromised.
Cyber criminals have opted to use Google’s goo.gl URL shortening service in their campaign therefore; it is possible to follow the success rate of clicks which are estimated to be around 2.5 million from unsuspecting users.

It has been stated that till date eight different goo.gl URLs being used by W32.Phopifas (A worm that spreads through Skype and Windows Live Messenger).
It cannot be extrapolated that how many victims actually downloaded, extracted, and installed the Malware, the figures do show just how successful a simple social engineering ploy can be on instant messaging applications.