I agree Kinnell. Allowing an archive file into the inbox of our user Tim
is not a smart idea these days.
Dave, I take it your not the email admin for your location? Ask your SA
"Systems Admin" to see the logs of the bogus attachments. How many are
actually valid attachments? I have received 7 today in 3 hours and my
network is by no means large. What does tiny Tim do when he gets the
attachment readme.zip spoofed with his domain as the sender?
My current policy allows all zips out the door but quarantines
everything coming in. If the file is valid I simply release it to mail.
Done. Yes, there is some administration but its better than tracking
worms!
Once again, until When Symantec Corp. integrates with Active Directory
to allow file attachments by user/group then maybe I can be more lenient
with the policy. For now I only have the choice to allow of block
everything. I can't trust some of the non technical users in my
organization (marketing, accounting, etc). They ask "what is this" and
forward information to the admin every time they get something they
don't recognize. This is after being trained numerous times. They are
easy prey to socially engineered email.
Thanks
AD
Information Technology Group
-----Original Message-----
From: Jonathan Loh [mailto:kj6loh@yahoo.com]
Sent: Tuesday, March 15, 2005 1:49 PM
To: Kinnell
Cc: David J ONEILL; security-basics@securityfocus.com
Subject: Re: 543.rar attachment
Good luck teaching common sense.
--- Kinnell <kinnell.t@gmail.com> wrote:
Very true. However we are not looking to ban people from using e-mail
as a tool to pass important files; we are looking to keep Tim, the new
intern from a near college, from opening a stupid e-mail with a "your
wife knows you watch porn" subject and running a file in there that is
said to keep your wife from finding out.
The problem is between the keyboard and the seat, not so much on the
servers, but if we can't teach the users common sense then we need to
ban all files. Same goes for so many hot topic items
-Kinnell
On Mon, 14 Mar 2005 22:41:44 -0800 (PST), Jonathan Loh
<kj6loh@yahoo.com>
wrote:
Ok let's have a reality check.
Blocking archive files is easy by just writing a simple filter
looking for
various extensions. Pruning executable files means you will have to
use
that
same filter, open the archive, either extract the whole thing,
delete the
executables, and repackage the whole thing, or delete the
executables in
place.
Everyone can split large application files, or can be taught how,
and send
them
to be repackaged. Ever wonder how TCP and UDP work?
--- David J ONEILL <David.J.Oneill@state.or.us> wrote:
Gee, why not just block ALL email communication. That would save
you
some work too.
Archive files are a necessary part of communication and very
beneficial
in saving bandwidth.
Let's have a reality check ....
David J O'Neill
Senior Systems Analyst
State of Oregon
Department of Human Services
Office of Information Services
PH# 503.378.2101 ext. 280
email david.j.oneill@state.or.us
Jonathan Loh <kj6loh@yahoo.com> 03/14/05 02:21PM >>>
Ok that's a solution. But what I want to ask you is this. How
much
overhead
does it take to do this? Blocking archive files would be an
easier
method with
little overhead. Possibly with a reply to sender that your site
does
not
accept archive files.
--- Kinnell <kinnell.t@gmail.com> wrote:
On the network I'm a member of we block all exe files sent
inside
the
rar or zip, so even if it is sent the file will be 0byted.
Wouldn't
that be a better method? otherwise if you block all bz2, zip,
rar,
etc... then you will block a lot of useful communication
-Kinnell
On Fri, 11 Mar 2005 16:49:16 -0500, adisegna@siscocorp.com
<adisegna@siscocorp.com> wrote:
Sean, I have to disagree with you. Any file that that can
encapsulate an
executable file should be blocked (IMO). ZIP files are one of
the
biggest carriers of malicious content these days. I don't make
it
a
habbit of trusting my users no matter how many times they get
trained.
RAR extraction tools are not part of the software image policy
on
my
network so users are oblivious to the file blocking. What is
your
solution?
Thanks
AD
Information Technology Group
Security Identification Systems Corporation
-----Original Message-----
From: Sean Crawford [mailto:sean01@accnet.com.au]
Sent: Tuesday, March 08, 2005 9:39 PM
To: security-basics@securityfocus.com
Subject: RE: 543.rar attachment
---> -----Original Message-----
---> From: adisegna@siscocorp.com
[mailto:adisegna@siscocorp.com]
---> Subject: RE: 543.rar attachment
---> I just recently got the same executable inside .rar. I
extracted
the
---> dddd.exe and ran a scan on it. Norton Corporate 9.01
didn't
find
---> anything (as of 4 days ago). I wasn't about to double
click
this
exe on
---> my corporate network. Block the rar extension on your
mail
server.
--->
rar is a valid compression format...blocking it isn't a very
good
solution.
2 cents.
Sean
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