Security Basics mailing list archives
RE: 543.rar attachment
From: <adisegna () siscocorp com>
Date: Wed, 16 Mar 2005 11:49:11 -0500
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
thatsame 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
themto 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 usJonathan 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
therar 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 canencapsulate anexecutable file should be blocked (IMO). ZIP files are one of
the
biggest carriers of malicious content these days. I don't make
it
ahabbit of trusting my users no matter how many times they gettrained.RAR extraction tools are not part of the software image policy
on
mynetwork 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. Iextractedthe ---> 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
thisexe on ---> my corporate network. Block the rar extension on your
server.---> rar is a valid compression format...blocking it isn't a very
good
solution. 2 cents. Sean__________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
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Current thread:
- RE: 543.rar attachment, (continued)
- RE: 543.rar attachment Sean Crawford (Mar 16)
- Re: 543.rar attachment Jonathan Loh (Mar 15)
- Re: 543.rar attachment Kinnell (Mar 15)
- Re: 543.rar attachment Jonathan Loh (Mar 15)
- Re: 543.rar attachment SAMIR SHUKRI (Mar 16)
- Re: 543.rar attachment Kinnell (Mar 15)
- Re: 543.rar attachment David J ONEILL (Mar 15)
- Re: 543.rar attachment Jonathan Loh (Mar 15)
- Re: 543.rar attachment David J ONEILL (Mar 15)
- Re: 543.rar attachment Micro Kluge (Mar 16)
- FW: 543.rar attachment adisegna (Mar 16)
- RE: 543.rar attachment adisegna (Mar 16)