[extropy-chat] [comp] Protect an exe?

[Alejandro Dubrovsky]

On Tue, 2004-01-27 at 11:22, Emlyn O'regan wrote:
> Here's the question... Does anyone know how to make an exe detect that it's
> file size has changed, and warn the user if it has (because it's probably
> been virus infected)? Or any other way to make an exe protect itself /
> detect problems? I'd ideally like to find a method that doesn't involve
> coding (ie: something that takes and exe and modifies it after the fact),
> but I might be willing to add code for really cool solutions. I just want to
> protect the users as much as possible, and make sure that an virus picked up
> has very little chance of spreading further.
> 
It would only be partially useful.  Viruses tend to modify entry point
to jump to their location, so they run before anything else, even the
size checking code.  They tend to return control afterwards so as not to
give themselves away, so the size checking could detect it after it has
propagated.  This would be useful so they could warn other people but a
net-savy virus would have spread beyond their control by then.
alejandro