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100 Email Bouncebacks - Welcome to Backscattering
distefano links to a story on Computerworld, excerpting: "E-mail users are receiving an increasing number of bounceback spam, known as backscatter, and security experts say this kind of spam is growing. The bounceback e-mail messages come in at a trickle, maybe one or two every hour. The subject lines are disquieting: 'Cyails, Vygara nad Levytar,' 'UNSOLICITED BULK EMAIL, apparently from you.' You eye your computer screen; you're nervous. What's going on ? Have you been hacked? Are you some kind of zombie botnet spammer? Nope, you're just getting a little backscatter — bounceback messages from legitimate e-mail servers that have been fooled by the spammers."
A few every hour? This weekend marks the second weekend in which I got several hundred bounces in a single night!
This story was preceded less than a month ago:
https://tech.slashdot.org/article.pl?sid=08/04/08/2258246
I had a bunch of these back then, now they are happening again. Here is some information about the subject.
http://spamlinks.net/prevent-secure-backscatter.htm
You should only get NDRs from your own ISP, as I undestand it. The other mail admins are being fooled by your spoofed return address, and should know better.
Where's the news here? I've been getting these for years. It's so bad that I filter bounce messages to a separate account on the server to download and review at the end of the week. I get almost as much backscatter as spam, both over 1000 messages a week.
It is dangerous to be right when the government is wrong.
Ugh, care to elaborate? Anyway, I think the solution is simple. Just publish a giant list of all mail servers not configured properly. It wouldn't be hard to write a script, to verify if a domain is configured or not. It would function as a name and shame list. But more than that, all spammers would harvest from it, and absolutely smash the listed servers until they were forced to configure them properly.
Nope, I'm not getting anything - procmail on my honeytrap spam email account sees it and stops it with a few simple filters
So please try harder, spammers, or go and get extensions to your obviously miniscule penises so you no longer need to take you inadequacies out on the rest of the world.
Gentoo Linux - another day, another USE flag.
There's an easy way to filter out backscatter while preserving bounce messages that you care about (ie. ones about email that you actually sent):
1. Add your own custom header to all your outgoing emails. Doesn't matter what it is, but it should be unique, eg. 'X-Really-From-Richard-Jones: xsomesecretx'
2. MTAs include the original headers in bounce messages, so discard bounce messages which don't contain your custom header.
You can even be smart and sign the header based on the content of the email using a private key, which would make it unforgeable, but at the moment you don't need to do that.
Rich.
libguestfs - tools for accessing and modifying virtual machine disk images
I must have read at least 3 news stories about backscatter in the last week. Why is this only getting attention now when it's been a problem for years? Is it just because someone has coined a word for it?
I can remember years back when some spammer decided to use my domain name in their spam run. Hundreds of bounced emails every day and I cursed everyone of the dumb mail servers that mailed them; complete with original html email, images and any other crappy attachment. ("Hundreds" may be small potatoes these days, but they were a big deal at the time.) Just the very idea that spammers would supply a genuine reply address seemed so incredibly stupid, yet there they were; dozens of carefully worded variants of the same "naughty spammer, don't email me" reply. I could just see some smug sysadmin configuring their system with this badly thought-out garbage, thinking "ha! that'll show them!"
None of my mail servers since then have ever bounced spam or mis-addressed emails.
1280px wide layout but the column with the actual content in is only 200px the other 1080px are dedicated to adverts and sponsors
i think that computerworld site is a classic example of a site that cares nothing for its readers (like spam) and is only a means to an end, when a site has more space dedicated to advertising than content you know you've hit a spam site
funny how they are telling us about spam while promoting more adverts on a single page than a spam message has
I lost my "email for life" account (randeg at alum.rpi.edu) nearly five years ago because of backscatter. I got a lot of it because that address appeared in-the-clear in libpng and zlib documentation. The people at RPI did not understand the backscatter phenomenon, and I assume they are still getting plenty of it.
As a 9-year veteran of the anti-spam industry (with experience within the regulator, although I've left that behind me now and work in telecoms,) it's a REAL stretch for anybody inside the IT industry to take these kinds of comments seriously.
Anybody who says that 'legitimate' mailservers are sending backscatter instead of 5xx-ing the message in transit is wrong. Mailservers which send backscatter are NOT legitimate, EOL.
- A pissed off mail admin.
You're doing it wrong.
Start spreading the word:
"Anyone who sends spam is a terrorist!"
Add random bogus reason, like "spam finances terrorism" and tag a "think of the children" on at the end.
Sooner or later, someone in power is bound to fall for it.
/.Mattsson - My native language is not English, so please don't whine over linguistic errors. (That's lame anyway...)
It seems like the solution to "backscatter" has been around for quite a few years (SRS). I'm surprised how few of the commercially available anti-spam solutions use or interpret it.
At my company, we just looked at Barracuda (PoS), Pineapp, St. Bernards ePrism, MX Force, Postini, and some other things. None of them understand SRS and only a few of the tech contacts had even heard of it. Sad Sad. But they all seem to have hand-rolled "backscatter" protection that partially works.
It seems like everyone has an SPF record these days. But it feels like relatively few actually check them and almost nobody goes the full distance and uses SRS.
Imagine if you weren't allowed to use roads because a bus company complained about your driving 3 times. --skunkpussy
MY JEWELER COULD NOT TELL
IT WAS NOT A REAL ROLEX!
More information how to buy an AAA+ quality replica!
Helluvua lot of mail servers out there not configured "properly." I can't block some mail even from "legitimate" mail servers because they are not configured well enough some of my spam rules don't pick them up, so how would a "list" fix that?
As it is, the lists from the anti spam houses work very little. There are so many zombie mail servers out there, I guess, no one can really effectively police these things except through spam filters. And Google are the only folks who can afford a full time staff writing spam filter rules.
Any more properly used to mean not an open relay; now it can can mean not in the same network segment that does have spamming email servers. Lists just add to the insanity and often punish legitimate mail servers.
Dawn of the Dead
Unless you like playing around with your user's machines a lot, you should better implement that at the MTA level and configure your mail server(s) so that they include the header.
Sure ...
Or you could just use SPF, which basically does the same thing, only more elegantly.
SPF doesn't do the same thing at all. It relies on the receiver MTA to do something about the non-matching SPF records, which evidently many don't (or at least, I've got proper SPF records, but still get huge amounts of backscatter spam).
Rich.
libguestfs - tools for accessing and modifying virtual machine disk images
"go and get extensions to your obviously miniscule penises "
I think one of their products can help them with that.
The trick is to use the "header_checks" and "body_checks" to look for signs of the email having being sent out from your email server in the first place.
echo '[q]sa[ln0=aln80~Psnlbx]16isb572CCB9AE9DB03273snlbxq' |dc
Think Machiavelli.
Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
It used to really bug me, that someone was sending out spam and using my legitimate email address in the From, Return-path and Envelope-from headers. I began filtering out the "Spam received from YOU" type headers years ago. But what still bugs me about this is those people who set their systems up to add me to some domain based rather than IP address based block list based on these faked headers. For more than a year I have been unable to successfully send email to my insurance company due directly to this issue.
Then again, I have never regarded email as a reliable method of communication. Everything truly important goes with a read receipt request and if I don't receive one then I phone or send snail mail. I continue to be amazed by the number of screwups I continue to hear about where someone says "I never got [such and such] email."
If an MTA is sending backscatter, it is not legitimate, it is broken. The MTA should NOT be looking at the FROM header to determine where the error goes. Report 5xx during the transaction, sending MTA is responsible for routing it to the associated address.
Any MTA I get backscatter from goes right into my local incompetent.dnsbl zone.
One of the main reasons forums don't get hit by spammers is because the admin staff knows what they're doing. They lock down threads, respond quickly, and keep the software up to date. Temporary bans, and permanent bans... You also need a working e-mail address in order to register, which blocks an awful lot of spam. Finally, there's over 150 domains on the banlist for my forums... some of the most popularly used (by spammers) freebie e-mail accounts, like mail.ru.
Oh... and it helps to have a robots.txt file. Mine looks like this:
The forums are served up from a subdomain... the actual site shows up in search engines, but having the separate domain with robots.txt helps keep the forums off the search engines. If they don't know you're there, then they can't spam you.
If you believe everything you read, you'd better not read. - Japanese proverb
Much easier to write a list of mail servers which are configured properly. At 66 lines per page, I'd reckon on about 5 sheets.
Red to red, black to black. Switch it on, but stand well back.
Computer World trying to get street cred by re-hashing old and moldy.
Nothing new here, move along.
Rick B.
MailScanner, which ships with Fedora, includes a feature called watermarking. Like those that have already posted, it works by creating a custom header with a secret key that is used to add a quick little seemingly random text and puts it in the header. If mail is coming from a bounceback, MailScanner checks the message for a match on the header. If it doesn't see one, then you can have it act based on that scenario. After turning this on, I get zero bounceback/scatterback emails into my Inbox. A perfectly elegant solution that works well and is easy to implement.
It exists. See http://www.backscatterer.org/
Bring back Sirius Punk!
How about we change the delivery method. Instead of an email being sent to me and sitting on my server or service waiting for me to sort it, you send me the headers for the sender, subject, size, date, and attachment status while the message and attachments sit on YOUR server until I chose to pick it up or it expires. The reduction in bandwidth should pay for the increase in storage, and the spammers would have to leave their message sitting on a machine somewhere waiting for me to pick it up (hint, not gonna happen).
1. No servers flooding the net with messages.
2. Easily identifiable spam sources, making bot-nets less useful.
3. Reduced bandwidth as the system replaces the old one.
4. Allow email clients and webmail services to be configured retrieve every message for the few numb nuts that don't/won't get it.
5. Profit (via reduced long term cost).
Just spitballing...
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
A nice trick is to put a no-follow link in robots.txt and have a well linked but no-follow (and to humans, obscured) page that when accessed denies that IP from getting anything from the site for a certain amount of time.
Oh.
I've asked this question in Slashdot before, but I've never gotten a satisfactory answer.
There are 7633 messages in my gmail spam folder. Now let's suppose I'm new to the internet, and I read spam message #1. Do I want Viagra? No thanks. Message #2, still don't want Viagra. #3 no thanks, I'm fine.
Well, I didn't buy that stuff the first 7633 times you asked me THIS MONTH, but maybe if you ask me REALLY nicely with a few misspellings just once more, then I'll cave into my male inadequacies and buy prescription medicine from a sketchy online source.
Now I'm going to pretend I'm a spammer. I want lots of money. What benefit is there to me to send a single address more than say... 5 messages? (not per month. EVER) If it didn't make it through the filters the first time, it won't the 800th time, and the more messages I send, the more likely my recipients will learn to evade them. More importantly, a jaded audience won't be receptive to buy.
I can imagine that the newer scams could be useful. Like the ones pretending to be your bank. I've only received a few of those, and it took some thinking to realize that the facts didn't add up. But the normal viagra spam should only be useful in the very limited cases where a brand new user (8 years old?) who hasn't been exposed to it ever before reads one of the first messages and decided that it's a worthwhile endeavour.
My hypothesis are:
1) Spam is not used in the effort of making money, but as a way of crippling the internet for sport.
OR
2) The majority of spam is sent by poor, hungry and stupid script kiddies who are as of now still poor, hungry and stupid.
We have noticed a DRAMATIC increase in backscatter over the last month or so. It has forced us to configure our E-mail systems to automatically flag NDR's as SPAM and quarantine them. I cant wait until the next new method of spam shows up.
1. Only works for obvious spam. For non-obvious spam it means the user has to download it - which notifies the spammer of a known-good address. That means more spam. (Right now images do this, but images can be disabled while preserving the text.)
2. They'll just advertise in the subject line. Perhaps easier to filter, but seems like a losing battle to me.
3. How do you authenticate?
4. Allows people to associate an email address with an IP even if that IP/address never sends them email.
5. Completely fails to account for offline/IMAP use.
Some of this can be mitigated by having the receiving server fetch the mail when the client requests it, but that adds more problems.
1. I'm pretty much whitelisting by hand now, If I don't know you, I don't care what you put in the subject line, your stuff is gone.
2. Set a size limit on all the headers, no hex or encoding, plain text and straight IP addresses for the server holding the mail.
3. Their server sends me a key to pick up the message (a header I forgot), if a server sees the same key a thousand times in a minute or two... hmmmm...
4. Works both ways: Gmail Warning, The message you are about to retrieve is located on a server KNOWN to send spam... Continue?
5. If your offline you are pretty much working with the mail you already downloaded, right?
I'm not saying I have a perfect answer, but there are plenty of people that can figure it out, just like other ideas have been brought to fruition on the web, by cooperation of parties that have a mutual interest... and on this topic, it a BIG group and they have the brain power and bucks to make it work without rattling to many cages.
The point is to reverse it so that the abusers are left holding the bag, botted machines are quickly identified (and hopefully cleaned), and the free ride stops with the death of standard SMTP servers.
All I can offer is my idea of a starting point...
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
I think you are misunderstanding the poster. The point is-- do not accept nondelivery (aka "bounce") messages from senders with misconfigured SMTP relays. This would be very easy to implement: bounce senders always set the "MAIL FROM" field to "[less than][greater than]". So if you receive an email from "[less than][greater than]", check it against the list. If it's from a misconfigured server, drop it.
/. filter.
This is one area where greylisting (taking advantage of the SMTP protocol to implement some primitive challenge-response) does not work, because MTAs involved in backscatter are indeed real SMTP servers.
BTW, interpret the "[less than][greater than]" as the actual angle braces. Stupid
wait for infinite loop to finish..
repeat as needed.
Storm
> Ended up installing a barracuda
You better have changed the default settings, or you just added to the backscatter problem.
Done with slashdot, done with nerds, getting a life.
I suppose this qualifies as a mis-directed 5xx rather than backscatter, but... Exactly a year ago, coincidentally, I received "failure delivery" bounces from a Yahoo.com server, for email I never sent, apparently because the actual sender put my corporate email address in the Return-Path! You'd think Yahoo'd know better.
Gmail makes it easy to create multiple aliasii (and to send from those aliasii I think).
Append a plus followed by a word, and it resolves to the name before the plus. e.g. happypenguin+amazon@gmail.com goes to happypenguin@gmail.com account. Or use dots in your email address and the gmail address resolves to your account without dots e.g. ha.ppy.pen.guin@gmail.com goes to happypenguin@gmail.com account
You can then easily create a spam filter if an address is snarfed by a spammer.
This article says it better: http://somegirlwitha.com/2008/04/17/the-dot-plus-and-googlemail-gmail-hacks/
Happy moony