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Best Method For Foiling Email Harvesters?
Posted by
Zonk
on Sun Nov 12, 2006 06:42 PM
from the when-the-addresses-are-high-as-an-elephants-eye dept.
from the when-the-addresses-are-high-as-an-elephants-eye dept.
pjp6259 writes "One of the common ways that spammers generate email mailing lists is by harvesting email addressess from websites. But in many cases you also need to make it easy for your customers to reach you. I have found three common solutions to this problem: 1.) Use an image to replace your email address. 2.) Use ascii encodings for some/all of the characters. 3.) Use javascript to concatenate and/or obfuscate your email address. Which of these methods are most effective? Are email harvesters able to interpret javascript? What do you use?"
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Make people think to figure out your e-mail (Score:3, Interesting)
- Putting the e-mail in a distorted picture (like a captcha) - this is very difficult for spam crawlers to read
- Using a long human readable message "tset ta tset tod moc.reverse.each.word.prior.to.first.dot.for.addr
In general, your best defense is to employ some method that requires human interpretation.
Re:Make people think to figure out your e-mail (Score:5, Insightful)
Really, if all you want is your customers or prospects be able to reach you through a website, got yourself a contact form.. No way for a harvester to get your email address that way, and people usually don't mind filling in a contact form.. if you obligate your customers to "think" as you suggest, you're risking losing potential custemrs which is simply not worth it. Besides, it makes you look very unprofessional.
Parent
Re:Make people think to figure out your e-mail (Score:5, Informative)
Parent
Re:Make people think to figure out your e-mail (Score:5, Insightful)
Bots tend to populate all form fields.
That would be the easiest step.
You could go a step further by having a text field that is hidden by a style="display: none;" and make sure that is empty as well.
Parent
Re:Make people think to figure out your e-mail (Score:4, Insightful)
Parent
Re:Make people think to figure out your e-mail (Score:4, Insightful)
Parent
Re:Make people think to figure out your e-mail (Score:5, Funny)
Parent
Re: (Score:3, Interesting)
I wonder, then, if adding the word 'dot' to your e-mail address would deter bots. Probably not, though. They'd probably just try all permutations of '.' and 'dot'.
Re:Make people think to figure out your e-mail (Score:4, Insightful)
1. The forms usually ask for your name, address, and other stuff.
I have never seen an admin restrict themselves to just asking for your email.
It's very typically set up along the lines of: tell us about yourself and we will
respond.
2. Your submission does not get copied to your "sent" folder so you forget you ever
communicated with the company. I like to keep a record.
Parent
Re: (Score:3, Insightful)
Re: (Score:3, Insightful)
The problem with doing either of those things is that they could be hard to read and/or confusing. If you're dealing with customers, you don't want them to get confused, fed up, and not buy your product/services.
Personally, I think the only way to handle it is to keep everyone's personal e-mail address off of the web page, and use generalized e-mail address like "sales@your-domain.com", "contact@your-domain.com", or "support@your-domain.com". Have it be someone's job to review incoming e-mail to these ad
Re:Make people think to figure out your e-mail (Score:5, Funny)
Parent
Re: (Score:3, Funny)
When the light shines through the fascia of the machine it powers up for a few minutes and opens a connection which is bounced around my diamond CPU initiating the SMTP process.
If you get the timing incorrect then the suns rays will instantly vaporise you.
So far I
Re:Make people think to figure out your e-mail (Score:5, Funny)
Parent
Re:Make people think to figure out your e-mail (Score:5, Interesting)
I predict Technical solutions will continue to fail to solve the spam problem, because it is not primarily a technical problem. It is a moral problem. Spammers (whoever they might be) are not respecting people. They are disrespecting us in order to get some money. Their values put dollars above the needs of anonymized people.
Until the moral problem can be solved adequately through accountability or other means, we are stuck with technical "solutions". Hopefully the solutions keep in mind the original intent of the technology or else we will continue to spend our time "jumping through hoops" rather than actually accomplishing work.
While a captcha does require human intervention, it makes it more difficult for a "normal" user to access. Same with nameIhatespam@domain.com or nameih8spam@domain.com or name @ domain.com This requires manual work and appears "unprofessional" Such confusion creates a barrier to effective communication.
Sure if you are on the "hackers are us" website such tricks are fine, 100% geeks, all interested in spending time re-typing information.
However if your audience is not technical, has any kind of failing eyesight (many over 60), or limited patience (the entire web audience) you had better keep it transparent for the end user. This is where javascript has served us well.
In recently gathering information from hundreds of manufacturing websites, I've found that the "cuter" the tricks, the less likely I am to pursue a working relationship with that manufacturer.
There are still tons of websites out there with unobscured email addresses in the HTML code and even in the text of the webpages. I don't see why spam harvesters would need to bother with javascript parsing engines when there is such a rich harvest of real email addresses out there.
I think people who are wiser than me need to consider how a community approach could seriously hamper spam. Maybe it is shaming the companies that build spam harvesting software. (we have imagination, we could 'make' them stop) I know that phoning and talking crossly to the wife of a spammer at an inconvenient time certainly created a stress reaction in her, which probably translated into stress reaction at their dinner table etc... I made the social cost of spamming high by phoning their 1800 number (costs them $0.05/minute). I made it real, I humanized my email address by "calling them on it" and complaining about their practices. (they still spam)...
Filtering is huge, but ultimately we need to call peopel to social responsiblity, and that requires one of two approaches that I can see.
1. Grassroots community accountabiltiy/reaction to spam
2. Top down legislative control.
Its a war, but the war isn't for or against SPAM, the war is for and against respecting others on the NET.
Greg.
Parent
You can't have your cake an eat it too ... (Score:5, Insightful)
If you have a form to submit to on-line, tag it and let it go to the head of the class.
Re:You can't have your cake an eat it too ... (Score:5, Interesting)
I think you hit the nail on the head. Strictly speaking, if you want to use text and don't leave a plain text version of your e-mail, you are at risk of being inaccessible.
I made a contact form for my site to avoid harvesters. While spammers do have scripts to submit contact forms, it's easier to trick a robot based on it's form input than based on what the robot can parse from the page (e.g. put a hidden field called phone number and fail the form on the backend if it has a value since most spam bots will try to enter something, and make sure there is an HTTP_REFERER, or ask for the user to duplicate some text in a field that is on the page somewhere else).
Parent
Re: (Score:3, Interesting)
Take a form putting the email alias in the table, and write a simple HTML form control that clicking the submit button takes the text on the page ("example") and appends the '@' sign and the domain ("example.com") in a two-step process, and spits out a "mailto:" link as the final step.
From the user's perspective, you get a little box that has you
Form (Score:5, Interesting)
If people need to send you files, they can do so after you reply back to them.
Re: (Score:3, Interesting)
All it takes is one of the dickwads to manually figure out your form and then they all do it. In addition to whatever you have as your form, make certain you disallow HTML in any of the fields or they will own you.
I have one set to show that it all went through just fine but it really just ignores their entry. It has worked so far.
Personally I go for (Score:5, Funny)
Works for me.
Re: (Score:3, Interesting)
Re:Personally I go for (Score:4, Funny)
Parent
disallow Windows users (Score:4, Interesting)
I have one email that I use specifically for REPLYING to emails and that one is the one that gets the MOST Spam.
Re:disallow Windows users (Score:5, Interesting)
Har har.
Anyway, I did an experiment once years ago where I created a brand new mail account and turned off 'spam armor plating' (or whatever it's called) on Slashdot. Then I went about making my posts etc. To my surprise, I started getting messages rather quickly. It didn't take more than a week or two to start recieving enough unsolicited mail to shut the experiment down.
Fast forward to last year. I told a coworker friend about this. He didn't believe me. So I tried the experiment again and... uh.. actually I only got one or two messages over a period of two weeks. I'm not really sure what happened. It's as if they gave up on Slashdot.
I cannot draw any real solid conclusions from these experiments other than to say that yes, email addresses on websites do get harvested. Yes, you could disallow Windows users, but that wouldn't do a thing to protect any other user. The only possible way that would work is if spam harvesting apps ONLY happened on Windows machines, and let's be realistic, there's nothing to prevent that software from making its way to Linux etc. Once it gets harvested, it doesn't matter which OS you run, you can get spam just as easily.
It's a tough problem with no single solution.
Parent
Simply put the address in clear text (Score:5, Insightful)
However, on a personal site, images.
Re: (Score:3, Funny)
use a Table! (Score:4, Interesting)
Re:use a Table! (Score:5, Interesting)
Couldn't you equivalently do <span>jsmith</span>@<span>example.com</span> ? You still lose the mailto though..
(I suppose you could toss in <span style="display: none">fnarfnarfnar</span> or something as well, if you want to confuse matters slightly more)
Would copy/paste insert whitespace anywhere where you don't want it?
Parent
Re:use a Table! (Score:4, Interesting)
In the right column, create an e-mail address that is missing the first letter or more of the actual e-mail address. Put the missing letters in the left column.
For example, if your e-mail address is "jack@example.com", "ja" would go in the left column and "ck@example.com" in the right column.
Then
Parent
SpamGourmet.com (Score:5, Informative)
Makes it trivially easy to create a unique forwarding address for any website you care to visit, then set the domain of that site as an exclusive sender for that address.
If a 3rd party starts spamming you at that address, Spam Gourmet just drops it, but continues to deliver relevant mail.
Oh, and it's completely free.
Re: (Score:3, Interesting)
This spring I was shopping for a new SUV, interested in an Escape. I went to ford's web site and they had a "submit email address to have dealers in your area contact you". Sure
Publish your email address. (Score:4, Insightful)
Seriously, if we cower in fear, the spammers win. Obfuscating, Turing tests, whatever show fear.
Re: (Score:3, Funny)
Re:Publish your email address. (Score:5, Funny)
Parent
Re:Publish your email address. (Score:4, Insightful)
Indeed. I have noticed that almost everyone who is involved with stopping spam does not munge or hide their email addresses. Julian Haight is the only person that I can think off of-hand that does not publish his email address.
I've been publishing my email address since the late 80s, I'm not going to start hiding it now.
Parent
Re: (Score:3, Funny)
Re: (Score:3, Funny)
There is a simpler ingenius method. (Score:3, Interesting)
Exploit poor coding standards. (Score:3, Informative)
Decoy address to build a spammer blacklist (Score:5, Interesting)
Put 2 email addresses on your web site, the real one, and a 'decoy' one which is hidden from normal users (eg white-on-white text right at the bottom of the screen).
Any email that arrives at the 'decoy' address is parsed, and the sender added to a blacklist.
Just be unique (Score:3, Interesting)
That being said, I don't think spammers crawl the net looking for addresses so much. Their zombies have all the addresses they need. Just try to give out your email address to people that don't have an affinity for virus infections. In my case, I protect my customers so my address hasn't been abuse too heavily thus far.
Fuck 'em! (Score:5, Interesting)
Yes, I get quite a lot of spam. But with the usual techniques (greylisting, SpamAssassin, etc.) I only actually receive maybe half a dozen spam e-mails a day. And more importantly, all my actually valid e-mail still seems to get through just fine. I'm happy with it, and I get the personal satisfaction of being able to use my e-mail address wherever I damn well like without having to cower from spammers.
Reverse psychology (Score:3, Funny)
It's so obvious, they'd NEVER think to look there.
Another method.. (Score:5, Informative)
I then use separate email addresses for everything I sign up for. E.g. my bank email address is different from my health fund email address, which is different from my all of mp3 email address etc. I use a little code which isn't obvious(similar to a lookup table) to code each website into the username portion of the email address... That's why I'm a little annoyed at allofmp3.com at the moment, as I've supplied two email addresses to them on only two occassions, and both are huge spam recipients. So it's clear that not only does their financial arm sell my email address, but their online store does too.
This method is good for 2 reasons: It's very easy to direct all email from particular addresses straight to the trash should they become spam targets and secondly, it's very easy for me to figure out (such as the allofmp3.com case) who sold my email address to spammers and when.
Email Obfuscation (Score:4, Interesting)
My theory is that harvesters have enough email addresses out there to gather and that the spammers are too lazy/have no need to write algorithms that interpret these types of mailtos.
use: SPAM as your username (Score:5, Interesting)
I have found that using SPAM as your username works wonders
just post it right there on the webpage or leave it as a mailto:spam@example.com [mailto]
So many people use NOSPAMjohn@NOSPAMexample.com (remove the NOSPAM to reply)
or some variation of that, I tried using spam@example.com as my email address on Google Groups and previously on Usenet.
I got pretty much nothing. No spam. Not then, not now.
Since the email harvesters apparently filter out variations of addresses with SPAM, NOSPAM, DIESPAMMERS etc in them, once they filter out the "SPAM" part of spam@example.com they are left with @example.com which is not a valid email address.
Use Javascript (Score:4, Interesting)
We use Javascript. You don't want to make life more difficult for the person trying to correspond - the point is to raise the cost to the spammer. If they have to add a Javascript parser to their spider, it's going to slow them way down. It's not going to make financial sense for them to do a custom solution for each site (and if they do, the "image" methods will break down as well).
When someone writes to me and says "reply to joe at gmail dot com" (or whatever), they generally don't get a reply. Why is their time more valuable than mine?
How my Host does it (Score:4, Insightful)
When the mail server gets an incoming email, it sends a request back to the "sending" email server listed in the headers. Since most spam is sent with falsified headers, the reply from the "sending" email server will respond that no mail was sent. Then my host mail server simply dev/nulls the spam. In the case of real mail, the sending server responds that it did indeed send the mail and my host then delivers it.
The only troubles I've run into are servers that don't support "sender verify". If the email doesn't get a verification message, its returned to the sender. Oddly enough, of the servers I've found that don't support "sender verify" they have been IIS servers. While there are still other IIS servers that do support it, I find it interesting that most of the servers not running IIS seem to have this feature turned on.
The nice thing about it is 90% of the spam never reaches a mailbox, and the filters from Spam Assassin catch the rest. This also removes the image only spam.
-Goran
Re:I take a modified approach to the 'image' metho (Score:3, Insightful)