Polish National Bank sends their customers TOS updates on CD they mail to them. So that they put it in their computers. A CD from a letter. And click on a PDF file. From a CD from their mailbox. Talk to your parents about taking CDs from strangers :(
Update: the CD contains an .exe and an autorun starting it. I was kind of hoping that this is a scam, and it seems more and more like one. The CD however is nicely branded by a bank and was addressed to my parents by name.