SANS Internet Storm Center, InfoCON: green reports “Skype 'worm' whinnies…, (Tue, Dec 19th). It appears that the possible Skype “worm” that we reported on yesterday is actually more of a Trojan Horse…”
One more time: an attachment, whether it shows up in email, IM, Skype, floppy disk, USB tab or in the transporter room, is from an untrusted source until you can confirm what it is, where it comes from, why its here and whether you should click on it. There are no trusted sources. “Click here for something really cool” is not an offer you should be taking up!