Cybercriminals posing as Skype messages posing as messages from the service. Email claiming that you have changed your password has been changed, but a file is attached to the email. If you make the mistake of unzipping and executing its contents, you run the risk of infecting your PC. The malware is detected by Sophos products as Troj/Backdr-HN, which opens a backdoor onto your computer, giving remote hackers access to your system. The danger is, of course, that users worried by the recent worm will be frightened that their Skype password was changed without their consent.”]
Source: https://nakedsecurity.sophos.com/2012/10/11/malware-attack-skype-password/