Ben Parker wrote:

>Only Sircam seems to use this   filename.filetype.xxxx  format, designed to
>automatically invoke some program on the user's machine which then results in
>the infection.  I have seen at least a dozen different filetype endings:

No. The double file type is to trick users. By default Windows hides file
extensions, so the last and real filetype on those machines is hidden. The
middle one is then visible, like doc, or txt, and the user thinks it is
safe to click on it, as it clearly isn't a program.

Don.