Slashdot Mirror
A New Type Of Realtime Blocklist: The SURBL
Glamdrlng writes "The SURBL, or "Spam URI Realtime Blocklist", represents a nexus of RBL's and content filtering that may bring us one step closer to a spam magic bullet. While traditional RBL's perform a DNS lookup on the connecting mail server, SURBL's take this a step further by parsing the text of the email looking for URI's and doing a lookup on those web servers. They also prevent "joe jobs" by maintaining a whitelist of legitimate web servers whose domain names may show up in spam messages, e.g. EBay, Paypal, Microsoft, etc. The only requirement to implement the SURBL is a plugin on your MTA such as spamassassin that can parse the body of each email. While there is no MTA that directly supports SURBL's without a plugin, the author hints at one being in development."
Blocking URLs is an "ACTIVE" measure - and one that opens very bad
possibilities for abuse. While the While-List would protect against
this it will protect the BIG players on the market - it can still
wreak havoc on small/medium enterprises - e.g. a competitor of a
(pretty much) 'niche' firm could get a spam out advertising the
COMPETITOR in order to get HIM blocked...
Or - the other way around - a company gets itself a whitelisting
(via a "fake" joe-job on itself) and then continues spamming...
Please stick to PASSIVE measures! They can't be abused...
This article advocates a
(x) technical ( ) legislative ( ) market-based ( ) vigilante
approach to fighting spam. Your idea will not work. Here is why it won't work. (One or more of the following may apply to your particular idea, and it may have other flaws which used to vary from state to state before a bad federal law was passed.)
( ) Spammers can easily use it to harvest email addresses
( ) Mailing lists and other legitimate email uses would be affected
( ) No one will be able to find the guy or collect the money
( ) It is defenseless against brute force attacks
( ) It will stop spam for two weeks and then we'll be stuck with it
(x) Users of email will not put up with it
( ) Microsoft will not put up with it
( ) The police will not put up with it
( ) Requires too much cooperation from spammers
( ) Requires immediate total cooperation from everybody at once
( ) Many email users cannot afford to lose business or alienate potential employers
( ) Spammers don't care about invalid addresses in their lists
( ) Anyone could anonymously destroy anyone else's career or business
Specifically, your plan fails to account for
( ) Laws expressly prohibiting it
( ) Lack of centrally controlling authority for email
( ) Open relays in foreign countries
( ) Ease of searching tiny alphanumeric address space of all email addresses
( ) Asshats
( ) Jurisdictional problems
( ) Unpopularity of weird new taxes
( ) Public reluctance to accept weird new forms of money
( ) Huge existing software investment in SMTP
( ) Susceptibility of protocols other than SMTP to attack
( ) Willingness of users to install OS patches received by email
( ) Armies of worm riddled broadband-connected Windows boxes
(x) Eternal arms race involved in all filtering approaches
( ) Extreme profitability of spam
( ) Joe jobs and/or identity theft
( ) Technically illiterate politicians
( ) Extreme stupidity on the part of people who do business with spammers
( ) Dishonesty on the part of spammers themselves
( ) Bandwidth costs that are unaffected by client filtering
( ) Outlook
and the following philosophical objections may also apply:
( ) Ideas similar to yours are easy to come up with, yet none have ever
been shown practical
( ) Any scheme based on opt-out is unacceptable
( ) SMTP headers should not be the subject of legislation
( ) Blacklists suck
(x) Whitelists suck
( ) We should be able to talk about Viagra without being censored
( ) Countermeasures should not involve wire fraud or credit card fraud
( ) Countermeasures should not involve sabotage of public networks
( ) Countermeasures must work if phased in gradually
( ) Sending email should be free
( ) Why should we have to trust you and your servers?
( ) Incompatiblity with open source or open source licenses
( ) Feel-good measures do nothing to solve the problem
( ) Temporary/one-time email addresses are cumbersome
( ) I don't want the government reading my email
( ) Killing them that way is not slow and painful enough
Furthermore, this is what I think about you:
(x) Sorry dude, but I don't think it would work.
( ) This is a stupid idea, and you're a stupid person for suggesting it.
( ) Nice try, assh0le! I'm going to find out where you live and burn your
house down!
There are millions of legitimate sites, and most of them aren't major sites like ebay, yahoo, etc. If I want to do a joe-job on an enemy small site, I can cause them a lot of pain by including their link. They'll have a dificult time someone wasn't spamming on their behalf.
I don't see this as the be-all, end-all for spam, but I do find it a very interesting and potentially very effective arrow for my spam-killer quiver.
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
I mean, really, who comes up with the names for these things?
Show me one self-respecting spammer who's going to quake in their boots at the threat of being hit with a "SURBL".
("Oh no.. please.. not the SURBL. Don't SURBL me.. Its too much... no.. No.. NOOOOOO!)
Why not just call it a "NERF" and be done with it?
I propose we come up with Spam deterrents with names like "Knuckle Duster", "Jagged Bottle", "Bloodied Crowbar" and "Bubba the Love Truncheon".
Norman Cook's Ode to Sl
Combine it with spamassassin, and you can whitelist emails from companies that you want to recieve email from. Heck, with spamassassin you can give it a very small weight, and adjust the results manually. Every bit of extra information helps, and just ignoring it because it is compiled by somebody else doesn't make sense to me.
The only requirement to implement the SURBL is a plugin on your MTA such as spamassassin that can parse the body of each email.
Anything which requires extra software on the MTA or client side is not a simple requirement as it cannotn be implemented universally. This is doomed to fail.
From the article:
Though the article's author feels that "most SC users probably make an effort to uncheck legitimate domains to prevent false reporting," I have read reports that some mail server admins claim that SpamCop's users are rather likely to mistakenly report ham as spam. So the domain whitelist becomes important, but what practices have the SURBL administrators put in place to prevent corruption with respect to sites reported to whitelist at surbl dot org?
Presently the only problem with this is that there are no plug-ins for the MTAs themselves yet. The plug-in is for spamassassin. That means that the message has to be transfered and passed onto Spamassassin before it can be dropped or tagged whereas, the other RBLs allow you to drop the connection before the message is transfered. This problem will be solved once there are plug-ins for the MTAs themselves.
But, I have to ask, why aren't existing RBLs like Spamhaus effective. They should be far more effective than the ~40% that I am experiencing.
Spammers could then post their web sites as search URL's on Google, MSN, etc.. If you block those URL's then lots of people would complain that they can't send Google entries. Even if you solved that, then what happens with sites like tinyurl.com? If you block them then you have liability and legal issues to think about. No doubt the spammers will script up a number of ways to cloak the marketeers site urls.
I am continually adding certain domain names to my spam filter, if found in text. I'd love it for this tool to do it for me, as long as I can trust the low false positive rate.
Mencken had it right. So glad that's old news.
This type of system is very abusable.
I know I have gotten spam reports from places like spam cop because people have included the URL of my website in their spam. My site had nothing to do with the spam other than the spammer was using an article on the site to back up his point of view.
This type of system could very easily be abused to blackhole many mailing lists.
We can't ever have a workable spam filter because of the adaptability of spam. However much you try, the spammers will come up with a way to circumvent your block. How long do you think that it would take for the spammers to figure out how to send emails that the whitelist software would mistake for legit? Nothing short of a trained monkey going through your inbox will sort this out effectively.
------- "A true friend stabs you in the front." -Eliot
A good way to start if you're running your own mailserver is to use an internal IP-based blacklist such as the one found here. It's incomplete due to Geocities limitations but send e-mail to that account and the guy running it will send you the whole file. It's a list that he's been compiling now for more than a year of IP blocks, mostly class Bs, that have virtually no useful SMTP traffic and should be completely cut off. This generally consists of the vast majority of Chinese, Korean and Brazillian DULs.
We've been able to effectively stop about 50% of the spam using these lists and save resources and bandwidth. What's left is to start RBL'ing the domestic DUL IP space (Comcast, SWBell, Bellsouth, etc.) on a class B-level until the ISPs start cracking down on their rogue users.
I've been playing with a honeypot email account for the last couple of months. Those "remove me from your list" links sure are a good way to get more spam (Spammers are lying scum). I hope this SURBL suggestion doesn't get implemented at the ISP level. Then I wouldn't be able to go the spammers site (carefully editing the URL as needed, and with Mozilla) and sign up my honeypot account for more penis enlargement spam!
My suggestion is to present the user with those images containing a word (like the one used by Yahoo! etc during registration) everytime the user needs to send a mail (before clicking Send). This is a reasonably difficult Turing-type tests which could weed out a majority of automated scripts/spambots.
An immediate problem with this scheme that I see is that for the words to be sufficiently random and crack-proof, they would have to be served in real-time to the mail program, and could need tweaks in current mail programs. A static list coded into the program might be too easy to break. This isn't too impractical, since an Internet connection is assumed during most email transactions.
Another problem, ofcourse is that it will not work with text-based mailers like PINE, but as long as it weeds out all the spam sent from all the freebie mail accounts we could see an improvement.
Comments/Suggestions?
An Indian-American Hindu committed to non-violent thought/speech/action alarmed by the global explosion of radical Islam
Let's coin a new term: YASSI for yet another stupid spam-related idea.
This boneheaded scheme falls into the same category as all content-based filtering systems: It doesn't address the most henous crime on the part of spammers, which is the consumption of bandwidth and network resources. And like other client-side/content-based filtering systems, the system will work about 12 minutes before the spammers figure out a way around it and then your system doesn't work. And of course, you'll have to constantly update it in order to make in effective, which means you have yet another piece of software that requires routine updating, slows down the mail service, your computer and everything in between. And after all that, you'll still get spam.
The main reason spam is prevalent is because SPAMMERS STEAL BANDWIDTH WITHOUT PAYING FOR IT. When you force them to operate from a single location, then they have to act ethically and then they have to pay premium money to spam, and then they go out of business because it's only economical when they steal resources.
You don't have content-based filtering on other primary methods of communication. It's a federal crime to go through mail; (at least before Patriot) you needed a court order to tap phones. E-mail should be an equally sacred communication medium that shouldn't be subject to "strip searches" before it hits your inbox. And this whole boneheaded scheme will NEVER stop spam in the first place, so let's stop pursuing these efforts.
RBLs are most effective right now. The worm invasion is evidence of that, as spammers are finding less IP space to operate from so they're engaging in more aggressive tactics to take over peoples' machines, which, hopefully sooner-or-later, will land these sleazebags in jail.
There is already a cure for spam - give everyone unlimited email addresses, give out different addresses to different recipients, and delete any email that receives spam (along with possibly sending an email of complaint to whoever you originally have that particular address to). The whole thing could easily be built into mail clients and supported by mail providers. It works fine for me. It costs me $35 to buy my own domain and a one off payment of about $30 to zoneedit to set up the mail forwarding. It works so well, and has worked for the least 3 or 4 years, that I almost suspect that there is some kind of conspiracy to overlook this method in order to promote other dubious methods.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
Unfortunately I really don't see anything new or original in this idea. Until they start prosecuting these morons, we're not going to have a viable solution. By morons I mean the people that are BUYING this crap, rather than sending it ;)
I agree with you, but there are some cases, such as APNIC networks which, unless you have reason to communicate with China or Korea, it's much easier to simply put a 218.* reject in your sendmail access file and avoid all the overhead to call the RBLs.
One problem we're seeing now is that some of the RBLs like Spamcop, automatically expire a blacklisted entry after X days. The spammers take advantage of this by playing around in huge Asian-Pacific blocks of IP space that give them plenty of addresses from which to rotate their spamming. One way around this is to blacklist the entire rogue regions, and then let the legitimate operations in those spaces contact you for permission.
For example, if Bellsouth is operating in the 68.* domain, and the lion's share of their IP space are DULs which shouldn't be sending port 25 traffic, it's a lot easier to BL the entire block and then redirect users to a form where they can submit legitimate SMTP relays and have them whitelisted.
The problem I have with RBLs (even though I love them) is that they're singly-IP-based, when there are some areas that just need to be wholesale blocked, and I've yet to figure out how to configure Bind to easily resolve IP lookups on blocks of addresses.
Sounds like a great idea especially for home users or some such but, as soon as you look at the bigger picture things start to break down. First of all, what about legitimate mailinglists? Some of them have hundreds of thousands of addresses. You want the administrator to have to go through and click a web page for each and every address on the list? Never gonna happen.
What about corporate use? Many legitimate emails go to a dozen recipients almost like a mailinglist. Think of the lost productivity with the senders clicking webpages for each reply and forward. Think of the dreaded Everyone group. Well, that would be an advantage but, you start to see what I mean.
Your idea is very similar in concept to a few others in that it requires a cost, someone reading a picture and clicking a button for the message to transfer. This scheme is better implemented by the various proposals that invoke a computational cost for each message transferred, like those from AOL Yahoo and Microsoft but, even these proposals all have major drawbacks and no one is rushing to implement them.
See the above list? Your post fits into:
(x) Requires immediate total cooperation from everybody at once
Also, accessibility, custom SMTP clients, yadda yadda yadda... but you've already realized your mistake so I'll stop now.
check this summary of spam methods.
http://netextend.com/junkmail
Overview
Solutions
Conclusion
Read the full report at
http://netextend.com/junkmail
For example, if Bellsouth is operating in the 68.* domain, and the lion's share of their IP space are DULs which shouldn't be sending port 25 traffic, it's a lot easier to BL the entire block and then redirect users to a form where they can submit legitimate SMTP relays and have them whitelisted.
Assuming you setup and honor a whitelist form, maybe. I regularly setup legitimate businesses on DSL connections from BellSouth. These are busiiness accounts with static IPs but, certain organizations like RoadRunner and AOL have decided that ALL BellSouth IPs should be blacklisted and they aren't interested in making exceptions. This became such a problem that my company has setup an SMTP relay on another ISP for our customers to be able to send mail. That's something we never wanted to do and would love to stop but...
One thing I've noticed a lot recently, is spammers including a big list of domains that have nothing to do with them in the text of thier junk mail. In the past 2 weeks, i've probally got about 10 spamcop reports for my customers, and in every case, my customer has had nothing to do with the junk mail, except for being listed in a list of about 15 URLs, that are not associated with the spammer. This system here says it has a whitelist for paces like ebay, paypal etc, but what about smaller people. They'd get blocked, and potentially lose business, due to something that they had absolutley nothing to do with.
Having just configured my email server with a ROBUST array of RBLs, I think this is a fantastic idea. I've been using the body_checks feature in postfix and manually adding violating URI's to create my own blacklist for several months now. I would love to benefit from a shared list. I don't care much for the white-list feature, that seems to me to create a backdoor for the spammer. Combined, RBL and private blacklisting (IPs and Addys) allow me to block 6000 plus spam A DAY. That's for a mere 150 plus users. Server side spam blocking using only Bayesian processing is an immense processor drain as is server side virus scanning. Look at it this way. Spammers need to make money. To do so you must be presented a URI to complete a transaction to make that money. They cannot easily change this URI without incurring cost so it will always be in the spam. Spammers who try to include too much "sales" content in their spams instead of a URI will be caught by a secondary bayesian filter. P.s. We have been successfully blocking encrypted URI's for months now. It's an easy rule to set up and legitimate users will never encrypt a URI. It's really quite beautiful.
But if it this approach catches on significantly, the more sophisticated spammers will just build their URLs in scripts.
And the rest of us will just block all e-mail that contains scripts. Yeah, I can't wait for that to happen...
This exact method is the basis of the MT-Blacklist comment-spam prevention system for Movable Type-based blogs. It works wonderfully, as it identifies spam on the basis of the one feature it must have to be successful--a link back to the spammer's site.
Do you have a *good* reliable geographicIP delegation table? I can never find one, and if I do, it's old, or grossly inadequate.
I'd love to have one; I wouldn't necessarily *blacklist* APNIC, but I would definitely rate-limit the entire APNIC to 28.8kbps into my network. I'm not sure it would "end" anything, but it would slow down spammers and/or cause them to give up on us.
I've been doing this with my e-mail server (link in sig) for at least a year now. You can view the entire list of domains I filter at the Indie-Mail site. I even have a right up describing the why and how of this system on www.icarusindie.com called "An Analysis of Spam." And this is probably the 20th time I'm hawked this method up on Slashdot.
The process is mostly automated but when it comes to blacklisting a domain, it's manual. You cannot automate it fully because legitimate domains make it into spams. yahoo, msn and w3c.org are the most common. Even without it being intentional on the spammers part. The automated part rips through e-mail logs pulling out who it's to, from and the subject and then all the urls. I can then clear out any entries that are going to account that aren't mine. And from there I go through and make sure the ones that do get added are actually spam domains.
A computer can't really tell the difference between a spam domain and a legitimate domain. Humans can.
Spam domains are blatently labeled like "medsforyou.com" contain random letters and numbers or have the spams images linked in the root. 8000hosting.com/ad.jpg is a big giant clue that this is a spam domain. I've seen links with 6 or 7 subdomains tacked on. I manually remove all the subdomain garbage and block the main one.
The link ripper not only yanks out the root domain (and any subdomains) but also the exact URL of what it was pointing to.
The main problem with anti-spam tools is that they rely on computers to find patterns. Spammers are not computers. They're idiots but not computers. And you can't get around the fact you need humans to be effective without causing colateral damage. Spammers do not always use computer identifiable patterns.
The other "problem" with this method is that it only says 50% of the bandwidth cost at max since the server has to recieve the message for parsing. So it's only good for people offering e-mail services like myself who can't risk being over zealous in fighting spam which could result in losing other people's e-mail.
ISPs are forced for the sake of bandwidth to use IP blacklisting while this sort of method would work as a secondary filter.
Again, there is no silver bullet. You cannot just rely on one form of spam protection if your goal is irradication. This method is just the least error prone when done properly. IP blacklisting can be like nuking a small villiage to kill a fly. This is a highly focused and reasonably sized flyswatter that may occasionally flak off some paint if swung too hard.
And never underestimate the number of domains spammers own. I get a dozen or so new domains to filter out ever few days. I may get spam but at least it's costing them real money to get it to me.
Ben
Work Safe Porn
check out the anonymous e-mail through www.icarusindie.com
Instead of a picture I just present a riddle or other question.
A human can search Google for the answer in order to be able to send their anonymous message. A program would need to be written and trained to be able to do that specifically for my web-site. I'm confident only someone with an academic interest in such a challenge would do it. And so far it hasn't been abused.
I use the same type of challenge but render the text to an image and add some noise on the Indie-Mail sign up page to keep bots off.
I also use a server generated ChallengeID that must be present which prevents anyone from using any page but the one I offer to even attempt to submit the form. If you don't use my page, the challenge file isn't generated on the server and without the file the server will ignore the request to process the form. You are also never sent the question number or question in text form. Everything the server needs to know about what question you're supposed to supply the answer to is stored in the server generated file that never leaves the server. And everything you need to know is in an image.
So far that hasn't been broken either. And if it is, I can adapt faster than bots can.
Ben
Work Safe Porn
I see one major problem with this, which is that Spammers might now be able to cause problems for legitimate websites simply by including their URL in the a Spam.
I'm a little sensitive to this since a spammer is actually Jo-jobbing one of my domains (not autopr0n), and I get hundreds of "user unknown" messages every day, along with a handful of messages telling me "my" email was blocked. It's really irritating.
But, if it's done right, it could work out pretty well. In fact, this would actually be effective against a lot of the current Spam out there, and kill Spam with off-site images.
Anyway, let me throw one countermeasure out there. Suppose spammers start including commonly mailed URLs (such as those on hotornot, yahoo, etc) in their spams in order to decrease the usefulness of these things. If this thing gets popular, expect to see a lot of Spam include a lot of random URLs the way they now include lots of random words. You'll also start to see things like "Javascript decryption" and other techniques to prevent machines from figuring out which, exactly, URL it is that is being advertised, rather then random noise.
autopr0n is like, down and stuff.