[comp.virus] Viruses & System 7.0

DAVE@GERGA.TAMU.EDU (Dave Martin) (04/25/91)

The report on GateKeeper 1.2 made me start wondering about how viruses
would behave under System 7.0 (one of the feature points said that
GK1.2 had better compatibility with Sys7, adding that users & viruses
shouldn't notice any differences). Has anyone experienced a virus
under System 7.0 (beta, FC, etc.), and if so, did they behave any
differently. Are any of them completely incompatible in that they
simply crash the machine when they try to do their dirty work, or do
they work just as they always have. Anyone looked at the code enough
even to tell what they'd do?

Of course, compatibility of old viruses aside, I get this gut feeling
that Sys7 will open the doors for more viruses, and make old ones
spread more easily. How will SAM react to an infected file run from a
FileShare folder? Or if someone puts a disk with WDEF into a drive
while a shared folder is open. Will SAM or any of the other active
detectors warn you when a virus tries to get in from the back door?
Does the AppleEvent manager have any built-in precautions to prevent
viri from sending events out to programs? Or from interfering with VM?
I know, lots of questions. Maybe they've been discussed before, I
don't know -- just signed on a week or so ago. As semi-official
manager of a small (~20) network, and someone who has had to clean
Scores, nVir, & WDEF from most of them many times, I'm curious how
much more trouble to expect from System 7.0

Thanks.
Dave Martin, Geochemical & Environmental Research Group, Texas A&M University
DAVE@GERGA.TAMU.EDU  DAVE@DBM-GERG.TAMU.EDU  BROOKS@TAMVXOCN.BITNET  AOL: DBM

phaedrus@milton.u.washington.edu (Mark Phaedrus) (04/29/91)

DAVE@GERGA.TAMU.EDU (Dave Martin) writes:
>Of course, compatibility of old viruses aside, I get this gut feeling
>that Sys7 will open the doors for more viruses, and make old ones
>spread more easily. How will SAM react to an infected file run from a
>FileShare folder? Or if someone puts a disk with WDEF into a drive
>while a shared folder is open. Will SAM or any of the other active
>detectors warn you when a virus tries to get in from the back door?
>Does the AppleEvent manager have any built-in precautions to prevent
>viri from sending events out to programs? Or from interfering with VM?

     I think all the hype over System 7 has caused a lot of people to
have incorrect ideas about what System 7 is like.  It does not
magically change all the rules of Mac programming; in fact, based on
my experience, it's more compatible with older software than System 6
was.  It does add new features, but in almost all cases it adds them
in a way that makes them very comparable to existing ones (just a
heckuva lot easier to use).
     FileShare, for instance, is almost exactly equivalent to
AppleShare, but without the dedicated server.  A program in a
FileShare folder (virus-infected or not) appears the same way as a
program in an AppleShare server folder, and viruses and
virus-detection utilities should react to it in roughly the same way.
Any virus detector worth its weight in RAM will check every resource
file that's opened, no matter where it comes from.  So FileShare
shouldn't create any new problems there (except for the problem of
uneducated users networking for the first time who don't realize the
potential for infection, and without any AppleShare administrator to
troubleshoot).
     There's no "protection" code in AppleEvents, as far as I know,
and the reason is simple; what good would it do?  Sure, a virus could
trigger spurious AppleEvents, but a virus under either System 6 or 7
can do things that are a heckuva lot worse; delete files, format
disks, crashing the system, etc.  Until code is added to make it
impossible for a virus to do these things (which brings up the age-old
problem: how to distinguish a virus from a legitimate request to
delete a file, etc.?), it seems silly to try to throw in code to keep
a virus from choosing Quit or whatever.
     Finally, virtual memory is exactly the same as physical memory,
only slower.  About the only VM-specific nasty a virus could pull off
would be to mess up or delete the virtual-memory storage file on the
hard disk; this would crash the system, but again, as crashing the
system is trivial under either System (the tricky thing to do is
*avoid* crashing it... :) ), no new security holes are added here.
     IMHO, System 7 will, if anything, make it a bit harder for
viruses and Trojan horses to propagate, if only by cleaning up the
System Folder a bit.  How many of us would even notice if somebody
slipped one more file into the morass of junk (whoops, vital System
extensions) that all of us keep in there?  By sorting things out into
at least a few subgroups, the new System will make it easier to keep
some sort of grasp of what's going on in there.

Internet: phaedrus@u.washington.edu        (University of Washington, Seattle)
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