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Archive-name: mail/anti-ube-pointer
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Maintainer: Jari Aalto <[email protected]>
X-Last-Modified: $Docid: 2002-09-01 Jari Aalto $
Announcement: "Anti-UBE pointers"
Availability
FAQ archive is at http://www.faqs.org/faqs/
This message is an excerpt of a bigger "Procmail Tips" section
"29.0 Anti-UBE pointers" available at http://pm-doc.sourceforge.net/
Terms used in this post
._UBE_ = Unsolicited Bulk Email
._UCE_ = (subset of UBE) Unsolicited Commercial Email
_Spam_ = Spam describes a particular kind of Usenet posting (and
canned spiced ham), but is now often used to describe many kinds of
inappropriate activities, including some email-related events. It
is technically incorrect to use "spam" to describe email abuse,
although attempting to correct the practice would amount to tilting
at windmills.
_Spam_ = definition by Erik Beckjord. "Some people decide that Spam
is anything you decide you want to ban if you can't handle the
intellectual load on a list." Remember, not to be confused with
real spam, which is unwanted bulk mail.
People are nowadays seeking a cure which will stop
or handle UBE. That can be easily done with procmail (under your
control) and with sendmail (by your sysadm). In order to select the
right strategy against UBE messages, you should read this section
and then decide how you will be using your procmail to deal with it.
Foreword and recommendation
There are two highly recommended software that you should check if
you're serious about taking actions agains UBE:
o `rblcheck' which has proven to be very efficient, fast and system
load friendly for ISPs that filter mail at MTA level.
o `Ricochet' which is a Perl program that examines
the headers to find out right complaint destinations. You no longer
need to be a Email header expert to understand how the headers have
been forged. To find the program, use google search
keywords "Ricochet perl spam"
29.1 NoCEM, CAUCE and others
"The war of spam -- pointers to reseurces"
http://spam.gunters.org/links.html
"NoCEM"
http://www.cm.org/
"The Coalition Against Unsolicited Commercial Email (CAUCE)"
http://www.cauce.org/faq.html
...The Problem: Unsolicited commercial mail, more commonly known as
"spam", is a growing problem on the Internet. If you've used the
Internet for any length of time, you've probably received
solicitations via mail to purchase products or services.
A Solution: A group of Internet users who are fed up with spam have
formed a coalition whose purpose is to amend 47 USC 227, the
section of U.S. law that bans "junk faxing", so that it will cover
electronic mail as well.
"SpamCon Foundation"
http://www.spamcon.org/
The SpamCon Foundation protects email as a
viable communication and commerce medium by supporting measures to
reduce the amount of unsolicited email that crosses private
networks, while ensuring that valid email reaches its destination.
"Spamcop - report bulk mail intrucions here"
http://www.spamcop.net/
"Lot of good articles about spam"
http://www.sun.com/sunworldonline/swol-12-1997/swol-12-spam.html
"Select mail court cases -- Lots of them"
http://www.jmls.edu/cyber/cases/spam.html
America Online, Inc. v. Cyber Promotions, Inc.,
Compuserve Inc. v. Cyber Promotions, Inc., etc.
29.2 General Filtering pages (more than procmail)
"Nancy McGough <[email protected]> - Mail Filtering FAQ"
.http://www.ii.com/internet/robots/procmail/qs/
.http://www.ii.com/internet/faqs/launchers/mail/filtering-faq/
"Information Filtering Resources"
http://www.ee.umd.edu/medlab/filter/ Doug Oard <[email protected]>
...This page lists all known internet-accessible information
filtering resources.
29.3 Junk mail and spam
"Spam FAQ"
ftp://rtfm.mit.edu/pub/Usenet/alt.spam/
http://www.cs.ruu.nl/wais/html/na-dir/net-abuse-faq/spam-faq.html
"The mail abuse FAQ"
http://members.aol.com/emailFAQ/emailFAQ.html
What is UBE, UCE, EMP, MMF, MLM, Spam, it is all explained here.
"Get that spammer -- A VERY GOOD LINK"
http://www.toppoint.de/~zoc/gspam.html
...All about Spam; traceroute, netabuse etc. Full of links and docs
"Spam Spade Tools -- Track down that spammer!"
Includes address digger, obfuscated URLs, reverse DNS, traceroute,
whois, rwhois, Dejanews author search, USPIS,
blackhole list check
"Fight Spam on the Internet!"
http://spam.abuse.net/
"Whois"
http://www.networksolutions.com/cgi-bin/whois/whois/
"Advertising on Usenet: How To Do It, How Not To Do It"
ftp://rtfm.mit.edu/pub/Usenet/advertising/
"Dealing with Junk Email"
http://www.jcrdesign.com/junkemaildeal.html
...What you should do (and not do) when you have been victimized by
a junk mailer. This document teaches you how to read headers in
order to trace the origin of junk mail, and includes detailed
examples to show you how it is done. Headers are designed for
computers to read, not people, so they can be a little hard to
follow. Therefore, I hereby grant permission to print or
electronically save a copy of this page on your local machine for
your personal use while tracing junk mail. Please check back for
updates and corrections, though.
o What Not To Do: Stuff that doesn't work
o What to do: effective techniques, including how to trace junk
mail back to its source
o Stay Calm (take a deep breath...)
o Stay Mad (don't get discouraged)
o How to identify the sender and who gives them Internet access
o Who to complain to, abuse addresses, online services
o What to say and how to say it, effective complaining
"Practical Tools to Boycott Spam"
http://spam.abuse.net/spam/
...We have been actively engaged in fighting spam for years. Recent
events, including pending court battles, prompt us to present this
page to the public. Fight spam to keep the Internet useful for
everyone.
o Filtering mail to your personal account
o Blocking spam mail for an entire site
o Blocking Usenet spam for an entire site
o Blocking IP connectivity from spam sites
o Other tools and techniques for limiting spam
o Sample Acceptable Use Policy statements for ISPs
"news.admin.net-abuse.* Homepage"
Timothy M. Skirvin <[email protected]>
http://www.killfile.org/~tskirvin/nana/
"Preventing relaying in Sendmail"
...This package adds two independent features to sendmail,
access control and relay control. They will be described here
simultaneously, but you can elect to include support for only one
of them (either one) on your mail server. Access control lets you
deny access to the server based on the senders envelope address or
his IP address. Relay control lets you decide who gets to relay
mail through your server.
ftp://ftp.xyzzy.no/sendmail/access.tar.Z
"Anti-Spam Provisions in Sendmail 8.8"
http://www.sendmail.org/antispam.html
http://mail-abuse.org/
http://www.informatik.uni-kiel.de/%7Eca/email/check.html#check_rcpt
o Preventing relaying through your SMTP port
o Refuse mail from selected hosts
o Restrict mail acceptance from certain users to avoid mailbombing
[1998-06-15 PM-L walter] Somebody's starting to exploit a hole in
sendmail 8.8, where giving a HELO longer than 1024 bytes causes
buffer overflow, and all following "Received:" headers are lost. If
it's done off a relay, we have no clue who sent it. There may be a
more elegant solution, but here's a quick-n-dirty procmail filter
for this stunt...
"Preventing relaying in Netscape Messaging Server"
http://www.tsc.com/~bobp/nms-no-relay.html
...discusses anti-spam configurations for Netscape
Messaging Server (NMS). These include proper anti-relay config,
spam filters, and using blacklists such as MAPS from NMS. I was
compelled to compile this page because of the extremely poor
Netscape documentation which includes anti-relay configurations
that are easily defeated. --Bob Poortinga <[email protected]>
"US Federal Trade Commission"
http://www.ftc.gov/
...staff publicized the Commission's UCE mailbox, "[email protected],"
and invited consumers to forward their UCE to it. spam complaints
<[email protected]>
"Misc"
http://www.junkbusters.com/
http://www.well.com/~jbremson/spam
29.4 Comprehensive list of spammers
"Against Spam -- The garbage collecting."
http://www.spam-archive.org/
To support this archive please forward mail spam to
<[email protected]>. Everybody is invited to bounce Mail-Spam
he/she has got to this list. This is a mailing list to distribute
actual spam-eMail. All incoming mail will be checked by subject and
from/sender-address wether it has already been distributed or not.
No discussions in this list. To discuss about this list please
subscribe to <[email protected]>.
To subscribe to _blacklist-update_ mailing list
TO: <[email protected]>
BODY: subscribe blacklist-update [email protected]
Mail <[email protected]> to discuss about blacklist if
your name is on it. (maintained by Axel Zinser <[email protected]>)
Get the updated blacklist from
ftp://ftp.spam-archive.org/spam/blacklist/
29.5 Misc pointers
Is there a way to block local users from spamming other sites?
Maybe somehow force sentmail to read a rc file that would maybe
then grab the from field and see if the user exists on the system
or not. Or run it through some sort of filters.
[philip] You can and should do this purely in sendmail. I ended up
crafting a check_from ruleset that verifies that the envelope
sender address is either a) not local; b) a local user; or c) a
local alias. At the time I did this mainly to force people to
configure their Eudora clients so they didn't say "Return Address:
[email protected]" but it also covers the outgoing bogus source
address spam case. For those interested in this kinda thing I've
(just) put it up for FTP:
ftp://ftp.gac.edu/pub/guenther/
"IBM's Secure Mailer: postfix - open source"
http://www.postfix.org/
[1998-12-15 PM-L Matthew McGehrin <[email protected]>] The
official project is known as 'IBM's Secure Mailer'. The
unofficial codename was Vmailer, but they had to rename that, to
Postfix to agree with the lawyers. I should know, I have been
alpha testing this mailer for the past year, and it so blazing
fast, its amazing. It's faster and simplier to use than sendmail,
and also faster and more secure than qmail. It works fine with
procmail. (look in my headers). set
"mailbox_command=/usr/bin/procmail" in /etc/postfix/main.cf
[1998-12-15 PM-L Liviu Daia <[email protected]>] it has
explicit hooks for both procmail and RBL. In fact it's incredibly
easy to setup, I got it compiled and configured (with an actually
usable configuration) in about 15 minutes after downloading it.
Adding masquerading and a virtual domain took another 2 minutes.
:-) You should really give it a try, it's faster than QMail and
_much_ faster than sendmail. So far, I'm quite impressed.
"Qmail"
http://pobox.com/~djb/qmail.html
http://www.qmail.org/
"Sendmail"
http://www.sendmail.org/
"Fetchmail -- old pop3 replacement"
ftp://ftp.ccil.org/pub/esr/
http://www.ccil.org/~esr/
http://www.tuxedo.org/~esr/fetchmail/
"Maildrop filter utility"
http://freshmeat.net/projects/maildrop/
...Alternative to procmail
29.6 UBE related newsgroups or mailing lists
alt.kill.spammers
alt.hackers.malicous
alt.2600
[1997-08-13 alt.privacy.anon-server by anonymous poster] Proper
etiquette demands you contact their ISP. However, if the ISP are
not interested in helping you, you should consider a posting in
alt.kill.spammers (or even alt.hackers.malicous or alt.2600) - give
as many details as you can about the spammer.
A certain spam-provider targeted the alt.hackers.malicious
newsgroup. Not the most sensible thing to do. The ISPs IPs were
found, their MX host was hacked. All their DNS entries was
published on alt.2600 (so that everyone could add filters to ignore
all mail from this company). Oh yeah, their password file also made
it to the group! The ISP then posted a complaint to alt.2600, much
to the enjoyment of everyone who took part. That host basically
died a horrible death. I'm pretty sure that not many people are
going to lose any sleep over this! I might as well mention that the
ISP's complaint mentioned that their "freedom" was being
abused. hehehe. Most of these postings can be seen in dejanews
or altavista archives of Usenet.
"SPAM-L mailing list and Doug Muth's Page"
http://www.claws-and-paws.com/spam-l/
... "The SPAM-L FAQ" - A FAQ for SPAM-L, an anti-spam mailing list.
This FAQ discusses how to join the list and what to post there, AND
it also delves into the technical aspects of spam. For instance,
the various kinds of forgeries seen in spams are discussed here,
along with information on how to recognise them. If you hate spam,
this is something worth checking out... "TheGoodsites List" - I
maintain this list, which is part of the Spam Boycott, to show
which Internet providers out there act responsibly when dealing
with spam. If you're looking for an ISP and want to know where they
stand on spam, this is the list for you.
Send an mail message to <[email protected]>
with the words "subscribe SPAM-L <First name> <Last name>" in the
body of the message (no quotes). f you would like to contact the
owner, the convention is the same as with all listserv lists. Just
send e-mail to <[email protected]>
29.7 Software: adcomplain -- Perl junk mail report
<[email protected]>
http://www.rdrop.com/users/billmc/adcomplain.html
Adcomplain runs under Unix, Windows-NT, and Windows-95. Adcomplain
is a tool for reporting inappropriate commercial e-mail and Usenet
postings, as well as chain letters and "make money fast" postings.
It automatically analyzes the message, composes an abuse report,
and mails the report to the offender's internet service provider.
The report is displayed for your approval prior to mailing.
Adcomplain can be invoked from the command line or automatically
from many news and mail readers.
#todo: url missing
[a user happy user reports] ...About 95% of all cases can be
traced correctly --- unless they come from a known spamhouse;
where complaining to them would not do much good anyway. Mailing
lists with strange Received-Headers also can present problems in
tracing
29.8 Software: Ricochet (Perl junk mail report)
http://www.vipul.net/ricochet/
<[email protected]> Vipul Ved Prakash
MailingList: <[email protected]> with subject
"subscribe"
A lot of unsolicited mail goes unreported because tracing the
origins of a possibly forged mail and finding the right people to
report to is complicated and time-consuming. Ricochet, a smart net
agent, automates this process. It traces the names and add resses
of the systems where the spam originated from along with the
servers that provide domain name resolution services to these
systems (in most cases their ISPs). Then it collects/generates a
list of mail addresses of tech/billing/admin/abuse contacts of
these system and mails them a complaint and a copy of the spam.
Detailed description of its workings can be found in the README
file that comes with the package.
29.9 Software: RBL lookup tool (C language)
[1997-12-04 PM-L Edward S. Marshall <[email protected]>]
...rblcheck is a lightweight C program for doing checks against
Paul Vixie's Blackhole List. It works well in conjunction with
Procmail for filtering unwanted bulk mail (under QMail, for
example, you can invoke it with the value of the environment
variable TCPREMOTEIP). rblcheck is extremely simple:
% rblcheck 1.2.3.4
where 1.2.3.4 is the IP address you want to check.
This is a quick note to announce the availability of a new tool for
using Paul Vixie's RBL blacklist (see http://mail-abuse.org/ for
more information about the blacklist itself, if you don't already
know). Most tools which use the blacklist block mail on a
site-wide basis. For many networks, this treads on both the ideals
of the administration, and on the perceived freedoms of the end
user.
Personally, I don't care either way. :-)
This tool was to fill the need I personally had to reject mail,
since one of the systems I receive mail through cannot, for various
political reasons, implement the available RBL filters on a
site-wide basis.
rblcheck is a simple tool meant to be used from procmail and
other personal filtering systems under UNIX in the absence of a
site-wide filter, as an alternative to imposing site-wide
restrictions, or as a means of imposing restrictions on systems
that cannot support the existing RBL filter patches.
Simply put: you hand it an IP address, and it determines if the IP
is in the RBL filter, providing the caller with a positive or
negative response. With the package, a sample procmail recipe is
provided, and examples of using it under QMail and Sendmail are
given.
.http://mail-abuse.org/
.http://www.isc.org/bind.html The official home page
.http://www.xnet.com/~emarshal/rblcheck/
It has only been tested under Linux 2.x and Solaris 2.5.1. Success
stories, patches, questions, suggestions, and flames can be
directed to me at <[email protected]>.
[PM-L Aaron Schrab <[email protected]>] Here is my rbl
setup, but, this depends both upon the format of the Received:
lines, and the way that mail passes through your mail system.
I currently grab the IP address from the first Received: header
inserted by my ISP (I'm a sysadmin at the ISP, so I have a good
knowledge of how mail gets passed around internally). Here's the
recipe that I use.
# if there's a Received: header from one of these servers, it's
# (probably) the right one
BACKUPSERVER = "([yz]\.mx\.execpc\.com)"
VIRTSERVER = "(vm[0-9]+\.mx\.execpc\.com)"
LOCALSERVER = "([abc]\.mx\.execpc\.com)"
# Match a header containing:
# Received: <anything> [<ip address>]) by <local server>
:0
* $ $SUPREME^0 ^Received:.*\[\/[0-9.]+\]\)$s+by$s+${BACKUPSERVER}
* $ $SUPREME^0 ^Received:.*\[\/[0-9.]+\]\)$s+by$s+${VIRTSERVER}
* $ $SUPREME^0 ^Received:.*\[\/[0-9.]+\]\)$s+by$s+${LOCALSERVER}
{
IP = $MATCH
# trim it down to just the IP address
:0
* IP ?? ^^\/[0-9.]+
{
IP = $MATCH
:0 W
* ! ? /home/aarons/bin/rblcheck -q $IP
{
SPAM = "$SPAM $IP is rbl'd$NL"
}
}
}
It seems to be a procmail issue with letting the IP info
from sendmail pass through to the rblcheck program. I have not
been able to find anyone using rblcheck successfully with
procmail as a delivery agent...
[1998-03-26 PM-L Edward S. Marshall <[email protected]> ] This is a
standard problem; you should be able to change the invocation of
procmail the same way as the example (run env, which in turn runs
procmail). Make sure that there is a '-p' argument passed to
procmail; this preserves the environment you're constructing with
env (newer sendmail revisions sanitize the environment for you, so
that's not really an issue).
If you're still having troubles, make sure you're using the latest
incarnation of rblcheck, with the latest supplied procmail recipe;
earlier revisions had rather insidious bugs.
[1998-03-26 PM-L Xavier Beaudouin (kiwi) <[email protected]>] Also it
seems that sendmail 8.9.0Beta3 has builtin rules. I use it with
sendmail 8.8.8 and tcpwrapper every day and there is about 80%
spam rejected. Sounds very good. In your /etc/hosts.allow just add
the following lines :
sendmail: ALL: spawn /usr/local/bin/rblcheck -q %a && \
exec /usr/sbin/sendmail -bs || /bin/echo \\
"469 Connection refused. You are in my Black List !!!\r\b\r\n"
&& \
(safe_finger -l @%h 2>&1 | /bin/mail -s "%d-%h %u" root)
In your /etc/inetd.conf just add this line :
smtp stream tcp nowait root /usr/sbin/tcpd \
/usr/sbin/sendmail -bs
And check that your sendmail is _not_ working as a daemon. That's
all. Also if you have huge queue you can add a /usr/sbin/sendmail -q
in the root crontab... This should help to send some waiting
messages. I think we can use this to wait for official 8.9.0
sendmail since there is some cf/feature/rbl.m4 there.
[timothy] ...I think there's a much more efficient way to do
this: you can compile sendmail -DTCPWRAPPERS and let it run as a
daemon
29.10 Software: mapSoN
Note: You can do exactly the same as below with procmail with one
of the listed procmail modules: pm-jacookie.rc. See the code.
"mapSoN (NoSpam backwards) -- The no spam utility"
http://mapson.gmd.de/
ftp://ftp.gmd.de/gmd/mapson/
Most spam filtering tools I've seen so far are based on procmail, or
a similar tool, and use a list of keywords or addresses to drop
unwanted junk mail. While this might be nice to filter mail from
known spam domains like "cyberpromo.com", it won't catch faked
headers.
mapSoN must be installed as filter program for your incoming mail,
usually by adding an appropriate entry to your $HOME/.forward file.
This means that mapSoN will get all your incoming mail and it will
decide whether or not to actually deliver it to your mailbox.
o First of all, an user defined ruleset is checked against the
mail. If any keywords or patterns match, the mail will be dealt
with according to your wishes. This is useful to drop some
sender's mail completely, or to sort mail into different mail
folders.
o If no rule matches the mail, mapSoN will check whether the mail
is a reply to an e-mail you sent, or whether it is a reply to a
USENET posting of yours. If it is, the mail will always be
delivered.
o If no signs of a reply-mail can be found, mapSoN will check
whether the sender stated in the From: header has sent you mail
before. If he has, the mail will pass. If this is the first time
you receive an e-mail from this address, though, mapSoN will
delay the delivery of the mail and spool it in your home
directory. Then it will send a short notice to the address the
mail comes from, which may look like this:
From: Peter Simons <[email protected]>
To: [email protected]
Subject: [mapSoN] Request for Confirmation
mapSoN-Confirm-Cookie: <some_weird_cryptographic_cookie>
The person who tried to contact you will then reply to this
"request for confirmation", citing the cookie stated in the mail.
When your mapSoN receives this confirmation mail, it will deliver
the spooled mail into your folder. Furthermore, the address will be
added to the database, so that mail from this person will pass
directly in future.
If no confirmation mail arrives within a certain time, mapSoN can
either delete the spooled mails, or send them to a special folder,
or whatever you prefer.
29.11 Software: spamgard
[similar to MapSon]
ftp://ftp.netcom.com/pub/wj/wje/release/sg-howto
...sppamgard(tm) screens from your e-mail unsolicited bulk mail. It
does this in a way that you only have to change things if you have
a new person from whom you _do_ want to receive mail; you don't
have to change things every time a spamster thinks of a new trick
to pull, or a new spamster comes along. And spamgard(tm) is
designed so that those who aren't in your "Good Guys" list can get
mail to you anyway until you put them there. The instructions for
them to get mail to you are simple and newbie-tested, but will
still keep out bulk mail. If you're on a mailing list you _want_ to
be on, there are provisions for accepting all mail from a set of
mailing lists that you specify.
29.12 Software: Spam Be Gone
"Spam Be Gone"
http://www.internz.com/SpamBeGone/ (open source)
...uses machine learning and artificial intelligence technologies
to examine incoming mail messages and determine their
priority... is more than just a Spam filter, it's a general purpose
mail message prioritiser. You train the system, telling it which
are good, and which are bad messages. As Spam Be Gone! learns it
becomes customised for each individual user.
Note: 2000-03 this software has changed a lot, so the above
comment may not apply any more. If you have used the latest version,
please send your impressions to this page's maintainer if they
differ from the text below.
PM-L R Lindberg & E Winnie <[email protected]> comments:
I have to agree with the recent comments about Spam Be Gone, I
found it tends to be inaccurate. I first set it up about a week
ago, followed the directions and trained it on several (15 to 20)
messages. One from each list we get, and the remainder from my
logs of SPAM messages.
The first day it missed about half the SPAM, and nailed about 1/3
of the real messages. So I tuned the key-words a bit, trained it
on about 100 more SPAMs and trained it on all the good messages
it nailed. Since then it has nailed every SPAM received, however
the second day it nailed about 20% of the good messages, which I
then trained it to like. Since then it has been nailing about
10% of the good messages, despite continual training. I also
added every list to the address book, and it still nails posts
from this list, and my wife's lace list.
I even went through my entire log of SPAM and trained it on every
one that didn't come out a 5 (bad). Being the kind of person I
am, I also checked after I trained it, and found four SPAMs, the
despite my training it that they were bad (5) came out as not so
bad (4). I don't dare kill 4's as far too much of my mail (like
this list) ends up as 4's.
For me, this program is not ready for prime time. If the comments
are correct that it only learns on Subject and From headers, it's
not even worth trying. Since lists use the TO and CC headers to
be identified, and there are several excellent other headers
(X-Advertisement comes to mind) that would be assests for killing
SPAM.
29.13 Software: TinyGnus - Emacs Gnus plug-in
._Availability:_ <[email protected]>
.http://tiny-tools.sourceforge.net/
._Platform:_ Win32 and Unix Emacs versions.
*TinyGnus* Is Emacs lisp extension package that integrates directly
to Gnus mail/newsreaders. It includes simple but efective UBE
fighting hotkeys that make it possible to complain bunch of UBE
messages at once. In order to use it, you have to have permanent
Internet connection and nslookup(1) tool. Features:
o USER MUST DECIDE and hand select WHICH IS *ube* MAIL. No software
can decide 100% which mail is UBE, so the responsibility is on
the Human user.
o User selects messages that are ube with Gnus select commands,
like (#, select current message)
o Hotkey C-c ' u examines messages' headers and runs `nslookup(1)'
for each Received header to determine *abuse* *spam* and
*postmaster* addresses where to send the complaint.
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