Fact Check

How to Protect Your Address Book

Will including a fake email address in your address book prevent you from spreading computer viruses?

Published Sep 12, 2001


Claim:   Including a fake e-mail address in your address book will prevent your PC from spreading computer viruses.



[Collected via e-mail, September 2001]

Here's a little trick you can use to stop the spread of pc viruses...

Create a contact in your email address book with the name !0000 with no email address in the details. This contact will then show up as your first contact. If a virus attempts to do a "send all" on your contact list, your PC will pop up an error message saying that: "The Message could not be sent. One or more recipients do not have an e-mail address. Please check your address Book and make sure all the recipients have a valid e-mail address."

You click on OK and the offending (virus) message would not have be sent to anyone. Of course no changes have been made to your original contacts list. The offending (virus) message may then be automatically stored in your "Drafts" or "Outbox" folder. Go in there and delete the offending message. Problem is solved and virus will not spread.

[Collected via e-mail, May 2002]


I learned a computer trick today that's really ingenious in its simplicity. I received it from a friend.

As you may know, when/if a worm virus gets into your computer it heads straight for your e-mail address book, and sends itself to everyone in there, thus infecting all your friends and associates. This trick won't keep the virus from getting into your computer, but it will stop it from using your address book to spread further, and it will alert you to the fact, that the worm has gotten into your system.

Here's what you do; first, open your address book and click on "new contact", just as you would do if you were adding a new friend to your list of e-mail addresses.

In the window where you would type your friend's first name, type in "AAAAAAA", Also use address AAAAAAA@a.aaa

Now, Here's what you've done and why it works: The name AAAAAAA will be placed at the top of your address book as entry #1. This will be where the worm will start in an effort to send itself to all your friends.
But, when it tries to send itself to AAAAAAA, it will be undeliverable because of the phony e-mail address you entered.

If the first attempt fails (which it will because of the phony address), the worm goes no further and your friends will not be infected.

Here's the second great advantage of this method: If an e-mail cannot be delivered, you will be notified of this in your IN BOX almost immediately. Hence, if you ever get an e-mail telling you that an e-mail addressed to AAAAAAA could not be delivered, you know right away that you have the worm virus in your system. You can then take steps to get rid of it!

Pretty slick, huh?

If everybody you know does this then you need not ever worry about opening mail from family or friends.


Origins:   This "helpful" bit of advice first appeared on the Internet in mid-August 2001, purporting to offer an easy-to-implement solution to prevent PCs that have picked up malware from being able to spread their infections by sending out virus-laden e-mails to other users. According to the advice, netizens need only add bogus entries (such as !000000 or 'AAAAAA@aaa') at the head of their e-mail address books to create an effective "shark account" that will gobble up unauthorized mailings to the full book.

There are two major problems with this approach that make it largely ineffective:

  • The advice assumes that viruses send out e-mail messages the same way humans do: Start up an interactive mail program (such as Microsoft Outlook), launch a form to initiate composition of a new message, then select names from the address book to insert addressees into the message header. But viruses don't work that way: They're programs that stealthily run in the background and use their own mechanisms for generating and sending mail messages; they don't interactively invoke mail clients, so they don't encounter the forms (and the address-checking routines attached to them) which are designed to avert human errors.
  • Viruses don't necessarily traverse address books from top to bottom and attempt to mail themselves to every entry in an infected system's address book, all in one message: They may start at the bottom of an address book, or they may randomly select entries from an address book, or they may harvest addresses from all sorts of other files resident on the infected computer, methods which would all avoid an 'AAAAAAA@a.aaa' entry placed at the head of an address book. Likewise, viruses may also mail out separate messages to each address they encounter, in which case a bogus address at the top of the address book won't do anything to stop the virus from spreading. (A message addressed to 'AAAAAAA@a.aaa' will bounce, but that won't prevent the virus from proceeding to mail itself via individual messages to everyone else listed in the address book.)

    Even if were possible to stop the spread of a virus via the ruse of a fake address book entry, that virus could still be doing damage to the infected user's system. Once an executable file has been opened and run, any virus it contains begins doing its dirty work — part of that dirty work may amount to mailing itself to others, but if the virus is programmed to do more than just replicate itself via e-mail, it will still be quietly wreaking havoc on the infected computer. Stopping a virus from sending infection-carrying e-mails will not necessarily halt whatever other furtively malicious activities it may be


    No computer user should follow advice about altering anything on his system without first fully understanding its nature. Though the current "helpful trick" is innocuous, there is no guarantee later versions will not circulate that instruct the credulous to do harm to their systems under the guise of helping them. Witness the May 2001 sulfnbk.exe hysteria, which duped thousands of users geared to take whatever advice turned up in their inboxes into deleting a key Windows operating system file from their home systems.

    The best advice for countering viruses has always amounted to investing in good anti-virus software and using the product regularly to scan for infected files. Second best is a caution against running executable files sent in e-mail. Prurient or lustful curiousity often fuels the spread of those infections, as users who should by now know better than to open applications that promise videos of some shocking political event or naughty encounters featuring the latest media hotties.

    Peek not lest you lose, not your soul, but your hard drive.

    Barbara "monkey C:\, monkey lose" Mikkelson

    Last updated:   21 April 2009