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Spam - origin, causes and cures.

08/05/08

Spam - origin, causes and cures.

Permalink 08:52:23 am by Eugene Gardner, Categories: Technical Tips

"How come", I was recently asked, "spam arrives in the form of Mail Daemon delivery failure notices" ? Sometimes dozens of such mail arrive saying that mail allegedly sent to someone you have never heard of could not be delivered. Here's the scenario.

A club or group sent out newsletters to all 50 members. One of those 50 recipients forgot to update his anti-virus software and so when he visited a dodgy website, an ActiveX or Javascript program ran and infected his PC. The infection read the contents of his address book and sent it on to a repository where it was merged with other stolen address lists and rented out to or sold on the highest bidder. The club member does not realize that he has been infected with a virus, but his PC is now known to be open to others wanting anonymity for their nefarious acts.

One of the purchasers of the list of e-mail addresses wants to invite 10 million people to buy viagra from him, knowing that if only .01% do, he will make thousands of pounds. So he runs one of many commonly available programs to send spam to those on the address list he bought. But not wanting to get caught by the authorities, rather than sending the mail from his own account, the mail will be faked to purports to come from one of the other addressees on the purchased list.

So for any of the addresses that have become invalid in the time between the day the list was originally compiled and the time the spam mail was sent, a delivery failure note will be generated and automatically sent to the address that the mail purports to come from. If that happens to be yours, you will probably receive many such messages from the Mail Daemon.

The advice, therefore, is to hide addressees from one another in multiple mailings by using private distribution lists or the BCC field in your mail program. Also, keep your Internet security suite updated as part of Eugene's routine housekeeping tasks.

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