Invasion of the Email Snatchers

They're sneaky. And stealthy. They're quiet and mostly unobtrusive, but once you've been visited by them, you'll know it. Because you'll be inundated with a seemingly never-ending stream of spam-mails.

They're email harvesting robots, and chances are you've been visited by one.

What these insidious creatures do is crawl your site, much like the search engine spiders do, and collect any and all email addresses they find there. Many of them crawl your entire site, following every link, gathering email addresses from your guestbook, your message boards, databases, and everywhere else they can get to.

What happens next is so sinister, so unthinkable; I can barely say it. They put your email addresses on CDRom and sell them- as opt-in lists. You've seen them, "20,000 targeted email addresses for only $29.95!", or my personal favorite, "Send 10 Bazillion emails- WITHOUT SPAMMING!!". What you didn't know was that it was YOUR email address they were selling.

To find out if your site has been visited by an email harvester, you only need to look at your logs. If your web host provides you with your stats, you can look in the Browser report for any of the following:

• EmailSiphon
• Crescent Internet Tool Pack v1.0
• Cherry Picker
• Email Collector
• Libwww-perl 1.0

If you don't have a stats program, you can examine your logs for visits from these agents. The easiest way to do this is to download them and open them in a program with a search function (like Wordpad). Then you can search for the names listed above.

So, what can you do to protect your site from these evil robots? Unfortunately, there's no single magic solution. There are, however steps you can take to discourage them.

The first thing you can do is create a Robots Exclusion file. This is simply a text file named robots.txt that you place in your root directory. What this file does is tells robots where they can and cannot go (as well as which robots can and cannot visit your site). The drawback of using this file to combat email harvesting robots is that as a rule, the robots.txt file is based on a sort of robot honor system. That is to say that you are assuming that any robot that visits will ask for and comply with the directives that you put there. Unfortunately, harvesting robots are typically ill-mannered robots that ignore this file. For more information on Robot Exclusion, visit the robots exclusion standard

A really fun solution is to use a cgi-script that punishes bad robots. What these do is to direct the robot to a page full of fake email addresses- lots and lots of them. So, what the spammer gets is a whole lot of bounced email messages, which will discourage them from visiting you again. The downside of this method is that they do also collect the valid email addresses. Also, most scripts of this type have a little disclaimer attached to them stating that they won't be held responsible for any legal issues that arise from the use of their script- and that has to make you wonder.

There are other scripts that hide your email address from the robots, but not your site visitors. This is a great solution for smaller sites that don't have more than one or two addresses listed. You can find both types of scripts at the robots exclusion standard

Another handy script is one that will check to see if a robot is friendly, and if not it will put it to sleep for say, 10,000 minutes. This will cause the robot to terminate the request and move on to another victim. $number = $ENV{REMOTE_ADDR};
($a,$b,$c,$d)=split(/./,$number);
$ipadr=pack("C4",$a,$b,$c,$d);
($name,$aliases,$addrtype,$length,
@addrs)=(gethostbyaddr("$ipadr", 2));

if ($name =~ /foo.com/i) {
$ENV{HTTP_USER_AGENT} =~ /emailsiphon/i;
$access_denied++;
sleep(10000);
}

The last option is, in my humble opinion, the best option. If you have the ability to modify your .htaccess file, you can specify certain host agents that are not allowed to visit your site using the mod_rewrite file. This effectively blocks the offending robots from ever touching your site. You should definitely check with your hosting provider to see whether or not you can make such a modification. Most hosts will be more than happy to make the modification for you.

For those of you willing and able to make the changes yourself, just add the following to your.htaccess file:

RewriteEngine on
RewriteCond %{HTTP_USER_AGENT} ^EmailSiphon [OR]
RewriteCond %{HTTP_USER_AGENT} ^EmailWolf [OR]
RewriteCond %{HTTP_USER_AGENT} ^ExtractorPro [OR]
RewriteCond %{HTTP_USER_AGENT} ^Mozilla.*NEWT [OR]
RewriteCond %{HTTP_USER_AGENT} ^Crescent [OR]
RewriteCond %{HTTP_USER_AGENT} ^CherryPicker [OR]
RewriteCond %{HTTP_USER_AGENT} ^[Ww]eb[Bb]andit [OR]
RewriteCond %{HTTP_USER_AGENT} ^WebEMailExtrac.* [OR]
RewriteCond %{HTTP_USER_AGENT} ^NICErsPRO [OR]
RewriteCond %{HTTP_USER_AGENT} ^Telesoft [OR]
RewriteCond %{HTTP_USER_AGENT} ^Zeus.*Webster [OR]
RewriteCond %{HTTP_USER_AGENT} ^Microsoft.URL [OR]
RewriteCond %{HTTP_USER_AGENT} ^Mozilla/3.Mozilla/2.01 [OR]
RewriteCond %{HTTP_USER_AGENT} ^EmailCollector
RewriteRule ^.*$ /badspammer.html [L]

While these are all effective measures to fight the Email Snatchers, there are new robots evolving every day. It's important to stay informed with the latest tools that the spammers are using. Some excellent sources of information can be found at:

Search Engine World
robots exclusion standard

Apache Today
robots exclusion standard

SpiderHunter.com
robots exclusion standard

--------------------------------

? Copyright 2001 Sharon Davis. When she is not waging war on spammers, she is the owner of robots exclusion standard, Work At Home Articles.net and the Editor of the site's monthly ezine, America's Home. In her spare time she reminisces about what it was like to have spare time. To subscribe to her free ezine, Click Here

---

How Spammers Fool Whitelists - And How to Stop Them

Effectively stopping spam over the long-term requires much more than... Read More

Winning the War On Spam

For years I didn't worry much about spam.But lately it's... Read More

How to Avoid Spam Complaints in Your Emails

Spam filters are responsible for deleting a high percentage of... Read More

Internet Tip of the Week: Information Overload

We receive so much information on the Internet, especially via... Read More

Which Spam Filter Is Best For You?

With the number of spam filtering solutions increasing each week... Read More

SPAM: A Nutrious Food or a Waste of Time?

Unless the filters on your computer are really good, you're... Read More

Stop Spam! New Spam Blockers

News last week that Internet service provider Verizon settled its... Read More

How You Can Avoid The New Dangers Of Spam

Until recently, spam has been an annoyance, a definite load... Read More

Edating Readers

One of our Australian clients sent out a campaign using... Read More

Why Your ISP Takes Bribes From Spammers

The lifeblood of the spammer is email. They need to... Read More

Spammer in the Slammer: Jeremy Jaynes Sentenced to Nine Years

Will other spammers take heed? Don't count on it.Jeremy Jaynes... Read More

Anti Trackback and Comment Spam Methods

What is spam ? ... Read More

Stuffing the Spammers!

I'm really, truly fed up with spam. Every day when... Read More

Getting Back To Basics.

While we all agree that there`s way too much spamming/junk-mailing... Read More

Sick Of Wading Through Spam?

It's a nightmare isn't it? You fire up your email... Read More

What SPAM Means: Stupid People Annoying Me

English, German, Italian - It's All SPAM To MeHas anyone... Read More

Internet Tip of the Week: Cease and Desist

While we all admit that unsolicited commercial email is a... Read More

Spam with Typos: Why Do They All Have Spelling Errors?

A friend asked me: I don't get it. Why do... Read More

Spam - Its Whats For Breakfast

The first thing I do every morning when I wake... Read More

Of Spam and Sandboxes

About a month ago I had the privilege of giving... Read More

Internet Theft and Fraud

My friends in the web hosting business have recently informed... Read More

The Business Of Sending Spam

You all tear your hair out in frustration every time... Read More

A War on SPAM: Attacking The Evil

As most small, medium and large businesses in this country... Read More

Spam The Spammer - Will It Work?

Spam is everywhere. It's the "in-box lunch meat" nobody likes,... Read More

Your Dolphin E-mail Caught In Spam Tuna Net?

Let me ask a couple of questions:If (potential) customers sends... Read More