Re: Double clicking on innocent looking files may be dangerous

From: Philip Stoev (philipat_private)
Date: Tue Apr 17 2001 - 00:36:10 PDT

  • Next message: neme-dhcat_private: "Advisory for Viking"

    This is true for Windows 2000 SP1, and no setting of "always show file
    extension" seems to be able to make Explorer display the entire filename. It
    must be noted, however, that the icon of the file is not the one of a text
    file, but rather the default icon with the Windows logo.
    
    When I attached the file in Outlook Express, the entire extension was
    visible at all places. Also, OE opened a Run/Save prompt when opening it,
    which is the behavior for HTA files, but not for TXT files on my machine
    (they open without prompt for me).
    
    And finally, a similar trick to make an ordinary shortcut point to the
    Control Panel or the Printers folder is described in the Tips+Tricks file on
    the Windows 95 CD, which means that this behavior has been there for a long
    time and maybe other tricks are possible with a carefully-chosen CLSID.
    
    Philip
    
    > Details:
    > If the file extension is certain CLSID e.g.:
    > testhta.txt.{3050F4D8-98B5-11CF-BB82-00AA00BDCE0B}
    > then Windows explorer and IE do not show the CLSID and only the .txt
    > extension,
    > while the above file is in fact .hta file.
    > Some exploit scenarios include leaving such malicous files on shared
    > resources or
    > sending them in archive by email.
    



    This archive was generated by hypermail 2b30 : Tue Apr 17 2001 - 10:17:14 PDT