What is spam?
Spam is the term used to describe unsolicited bulk messages sent by electronic means (compared to ‘Junk mail’, which is the term widely used to describe unsolicited bulk messages through the post).
However, unlike ‘Junk mail’ which is perfectly legal, spam is illegal through most of the world. The goods/services offered through spam messages are also often illegal or at least highly dubious.
Spam is also extremely dangerous. Besides the distasteful nature of much spam, and the disgusting nature of some, a lot of spam carries viruses, trojan horses and ‘worms’ – computer programs which are designed to harm, spy on or even enslave your computer.
There are many forms of spam; spam by email is the most dangerous, whilst spam attacks on websites is less dangerous but more annoying, as there is much more of it.
Why is spam sent?
Typically, the aim of email spam is to gather unsuspecting victims details to sell on to the highest bidder, or to produce more valuable spam databases. However a small core of spammers are going after your computer equipment – building a so-called zombienet, a network of computers that they can instruct to do their dirty work for them, their owners helpless to prevent it.
Website spam is usually simply undesirable and unsolicited messages advertising produces, services and other websites. Whilst very annoying, this is less dangerous.
There is some cross-over and a lot of website spam is potentially highly dangerous.
How do they get away with it?
Spammers use their zombienets to spam other computers – usually the computer at the end of a spam campaign belongs to someone entirely unaware of the problem. This is what makes it difficult for law enforcement authorities to stop the spammers.
How do we stop it?
The most effective way to stop spam is to prevent it from earning any money for the spammer.
Email spam should be quickly deleted – never open attachments on email from addresses you do not know, even if it purports to be from someone you know. Check with them first. If an executable file is attached, such as file ending in .exe, you absolutely must not run this file – these are highly dangerous files.
Never use the “unsubscribe” link on a spam email.
Website spam is more difficult to deal with. If untreated, a spam problem can quickly overcome your website costing you time, money and effort in manually deleting the comments.
To prevent spam, again we must try to prevent the spammer from making money, but this time it is done by raising the costs of spam, through tests to determine that the user is human and other methods of preventing the spam from getting through in the first place.
If you are under a deluge of spam, do not panic. You can implement a CAPTCHA to stop most of the spam from getting through.
A more long term solution is the use of a filtering system, such as the Akismet service from Automattic.
This site documents hundreds of possible solutions to spam, often complete with example code and methods.