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:
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
shuttle to Midway Beardstown .. Lockport Chicago limo O’HareEnglish, German, Italian - It's All SPAM To MeHas anyone... Read More
It seems like the volume of email spam has doubled... Read More
Spam, as defined in the context of computers, the Internet... Read More
Junk mail works. Why does it work? How does it... Read More
Spam filter is the solution that most people resort when... Read More
Unless the filters on your computer are really good, you're... Read More
With SPAM being such a problem it might seem the... Read More
Spammers get email addresses from web pages using programs called... Read More
One of our Australian clients sent out a campaign using... Read More
Before we start getting deep into the meat of this... Read More
1. Ignore Spam EmailDo not open an unsolicited email. Spammers... Read More
It's a nightmare isn't it? You fire up your email... Read More
Most of us have opened our email program and found,... Read More
It's no secret that the US economy has slowed down,... Read More
As the flood of spam increases end users are looking... Read More
A friend of mine received a chilling email message from... Read More
Effectively stopping spam over the long-term requires much more than... Read More
They're sneaky. And stealthy. They're quiet and mostly unobtrusive, but... Read More
When you receive an email telling you about a virus,... Read More
What is spam ? ... Read More
I'm sure you find spam just as frustrating and annoying... Read More
Why is someone from India, Africa, or elsewhere writing you... Read More
What comes to your mind when you think about your... Read More
A blacklist, as the name implies, is a list of... Read More
You just sat at your desk, opened your email account... Read More
Green Bay Hummer H2 SUV rentals ..I'm sure you find spam just as frustrating and annoying... Read More
It seems like the volume of email spam has doubled... Read More
Effectively stopping spam over the long-term requires much more than... Read More
It's a nightmare isn't it? You fire up your email... Read More
You may have already received a do not spam list... Read More
As most small, medium and large businesses in this country... Read More
My friends in the web hosting business have recently informed... Read More
In today's spam-filled email world, it's sometimes VERY difficult to... Read More
Why do so many people think I need to take... Read More
I'm really, truly fed up with spam. Every day when... Read More
Do you like spam? No, I'm not kidding. Everybody knows... Read More
Death by spam is now possible with a new device... Read More
We all hate spam and get way too much of... Read More
One of our Australian clients sent out a campaign using... Read More
With the number of spam filtering solutions increasing each week... Read More
Until recently, spam has been an annoyance, a definite load... Read More
Very often SPAMMERS take advantage of catch-all email setup on... Read More
Effectively stopping spam over the long-term requires much more than... Read More
Spam. You've all heard of the crazy pink meat in... Read More
Your message is not being delivered.If you send emails to... Read More
This review is taken DIRECTLY from a piece of "junk... Read More
2004 was really a year when the whole subject of... Read More
Stop intrusive pop-up ads and regain control of your online... Read More
E-mails now have a connection back to their servers. I... Read More
News last week that Internet service provider Verizon settled its... Read More
Spam Blocking |