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: : E-mail & Spamming Inquiries : Spammer has used my email address for spamming. Help! |
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Question: | Spammer has used my email address for spamming. Help! | Answer: | It is most likely that someone has your email address in their address book got infected with Klez and is unknowingly spreading the virus to everyone they've ever sent or received email from.
There is a variant of the Klez (an email worm) that looks though explorer's cache for e-mail, so someone having visited a page with your e-mail, having been infected, might also be the cause.
In addition, there are many ways in which spammers can get your email address. The ones I know of are :
1. From posts to UseNet with your email address.
Spammers regularily scan UseNet for email address, using ready made programs designed to do so. Some programs just look at articles headers which contain email address (From:, Reply-To:, etc), while other programs check the articles' bodies, starting with programs that look at signatures, through programs that take everything that contain a '@' character and attempt to demunge munged email addresses.
There have been reports of spammers demunging email addresses on occasions, ranging from demunging a single address for purposes of revenge spamming to automatic methods that try to unmunge email addresses that were munged in some common ways.
As people who where spammed frequently report that spam frequency to their mailbox dropped sharply after a period in which they did not post to UseNet, as well as evidence to spammers' chase after 'fresh' and 'live' addresses, this technique seems to be the primary source of email addresses for spammers.
2. From mailing lists.
Spammers regularily attempt to get the lists of subscribers to mailing lists [some mail servers will give those upon request], knowing that the email addresses are unmunged and that only a few of the addresses are invalid.
A different technique used by spammers is to request a mailing lists server to give him the list of all mailing lists it carries (an option implemented by some mailing list servers for the convenience of legitimate users), and then send the spam to the mailing list's address, leaving the server to do the hard work of forwarding a copy to each subscribed email address.
[I know spammers use this trick from bad experience - some spammer used this trick on the list server of the company for which I work, easily covering most of the employees, including employees working well under a month and who's email addresses would be hard to find in other ways.]
3. From web pages.
Spammers have programs which spider through web pages, looking for email addresses, e.g. email addresses contained in mailto: HTML tags [those you can click on and get a mail window opened]
Some spammers even target their mail based on web pages. I've discovered a web page of mine appeared in Yahoo as some spammer harvested email addresses from each new page appearing in Yahoo and sent me a spam regarding that web page.
4. From various web and paper forms.
Some sites request various details via forms, e.g. guest books & registrations forms. Spammers can get email addresses from those either because the form becomes available on the world wide web, or because the site sells / gives the emails list to others.
Some companies would sell / give email lists filled in on paper forms, e.g. organizers of conventions would make a list of participants' email addresses, and sell it when it's no longer needed.
Domain name registration forms are a favourite as well - addresses are most usually correct and updated, and people read the emails sent to them expecting important messages.
5. Via an Ident daemon.
Many unix computers run a daemon (a program which runs in the background, initiated by the system administrator), intended to allow other computers to identify people who connect to them.
When a person surfs from such a computer connects to a web site or news server, the site or server can connect the person's computer back and ask that daemon's for the person's email address.
Some chat clients on PCs behave similarily, so using IRC can cause an email address to be given out to spammers.
6. From a web browser.
Some sites use various tricks to extract a surfer's email address from the web browser, sometimes without the surfer noticing it. Those techniques include :
[1] Making the browser fetch one of the page's images through an anonymous FTP connection to the site. Some browsers would give the email address the user has configured into the browser as the password for the anonymous FTP account. A surfer not aware of this technique will not notice that the email address has leaked.
[2] Using JavaScript to make the browser send an email to a chosen email address with the email address configured into the browser. Some browsers would allow email to be sent when the mouse passes over some part of a page. Unless the browser is properly configured, no warning will be issued.
[3] Using the HTTP_FROM header that browsers send to the server. Some browsers pass a header with your email address to every web server you visit. To check if your browser simply gives your email address to everybody this way, visit http://www.helie.com/BrowserCheck/
7. From IRC and chat rooms.
Some IRC clients will give a user's email address to anyone who cares to ask it. Many spammers harvest email addresses from IRC, knowing that those are 'live' addresses and send spam to those email addresses.
This method is used beside the annoying IRCbots that send messages interactively to IRC and chat rooms without attempting to recognize who is participating in the first place.
This is another major source of email addresses for spammers, especially as this is one of the first public activities newbies join, making it easy for spammers to harvest 'fresh' addresses of people who might have very little experience dealing with spam.
AOL chat rooms are the most popular of those - according to reports there's a utility that can get the screen names of participants in AOL chat rooms. The utility is reported to be specialized for AOL due to two main reasons - AOL makes the list of the actively participating users' screen names available and AOL users are considered prime targets by spammers due to the reputation of AOL as being the ISP of choice by newbies.
8. From finger daemons.
Some finger daemons are set to be very friendly - a finger query asking for john@host will produce list info including login names for all people named John on that host. A query for @host will produce a list of all currently logged-on users.
Spammers use this information to get extensive users list from hosts, and of active accounts - ones which are 'live' and will read their mail soon enough to be really attractive spam targets.
9. By guessing and cleaning.
Some spammers guess email addresses, send a test message (or a real spam) to a list which includes the guessed addresses. Then they wait for either an error message to return by email, indicating that the email address is correct, or for a confirmation. A confirmation could be solicited by inserting non-standard but commonly used mail headers requesting that the delivery system and/or mail client send a confirmation of delivery or reading. No news are, of coures, good news for the spammer.
Guessing could be done based on the fact that email addresses are based on people's names, usually in commonly used ways (first.last@domain or an initial of one name followed / preceded by the other @domain)
Also, some email addresses are standard - postmaster is mandated by the RFCs for internet mail. Other common email addresses are postmaster, hostmaster, root [for unix hosts], etc.
10. From white and yellow pages.
There are various sites that serve as white pages, sometimes named people finders web sites. Yellow pages now have an email directory on the web.
Spammers go through those directories in order to get email addresses. Most directories prohibit email address harvesting by spammers, but as those databases have a large databases of email addresses + names, it's a tempting target for spammers.
11. From a previous owner of the email address.
An email address might have been owned by someone else, who disposed of it. This might happen with dialup usernames at ISPs - somebody signs up for an ISP, has his/her email address harvested by spammers, and cancel the account. When somebody else signs up with the same ISP with the same username, spammers already know of it.
Similar things can happen with AOL screen names - somebody uses a screen name, gets tired of it, releases it. Later on somebody else might take the same screen name.
As spammers not caring too much for invalid addresses, and with lists of email addresses burned on CDs and sold, this scenario is probable.
| last updated Nov.16.2003 | |
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