Re: head off email viruses: distinguishing documents from executables?

[Julien Olivier <julo altern org>]

On Tue, 2003-11-04 at 02:26, Steven G. Johnson wrote:
> As usual, I have been getting lots of MS email viruses on my GNU/Linux
> email account.  Occasionally, however, instead of trashing them, I marvel
> at the evil social engineering that goes into them, and I think about how
> a similar attack might be aimed at other systems, e.g. Linux.
> 
> One of the tricks seems to be to attach a .zip file of something that
> purports to be a document, but is actually an executable (readme.doc.scr),
> combined with an email ("Read this for our meeting tomorrow") that tricks
> the user into opening it.  One could conceivably do a similar trick with
> Linux (attaching a .tar.gz).
> 
> The basic problem is this: simply *reading* a file, no matter whom it is
> from, *should* always be safe...at least there is no technical reason it
> can't be, and this is what people expect from the real-world metaphor.
> But, of course, with MS, you open a document and launch an executable in
> the same way (double-click).  Similarly on a Mac.  And similarly (last I
> checked, admittedly a long time ago) with GNOME.  The only exception is
> the command line.  How does Nautilus handle this?
> 
> As a basic safety feature, when you double-click on an executable file,
> before you execute it you might pop up a dialog saying "This is an
> executable program, not a document, and it may run arbitrary commands; are
> you sure you want to launch it?" (with a check box to disable the warning
> for *that file* in the future).  By default, you may even want to disable
> click-to-run executables entirely, except for specially-created desktop
> shortcuts, since most people only need to launch executables from the
> menu, by drag-and-drop, or by double-clicking an associated document.
> 
> Sorry to bother you if you've already thought about this, but I figured it
> wouldn't hurt to be pro-active.
> 
> Cordially,
> Steven G. Johnson
> 
> PS. There are of course, other attacks if you can trick a user into
> opening a file, such as evil .tar.gz files that create dotfiles (or write
> in dot-directories), etcetera, when they are uncompressed from a known
> location (e.g. $HOME).
> 
> PPS. Sorry if this is misdirected; I couldn't find any kind of GNOME
> security list (which might be a nice idea if it doesn't exist).

Hmm.. isn't it exactly what Nautilus already does ?

-- 
Julien Olivier <julo altern org>