Spam, a contraction of rotten email (or junk email), is a global and massive phenomenon. And as long as email exists, this real problem will always exist. However, it is possible to significantly limit the effects of spam. To do this, you just have to use various anti-spam technologies wisely. In this chapter, the authors present the definitions of spam and its evolution, its objectives and impacts, as well as the different approaches and techniques used for detecting and filtering it.
TopSpam History
The real origin of the term “SPAM” comes from 1970 Monty Python’s Flying Circus skit. In this skit, all the restaurant’s menu items devolve into SPAM. When the waitress repeats the word SPAM, a group of Vikings in the corner sing “ SPAM, SPAM, lovely SPAM Wonderful SPAM” drowning out other conversation, until they are finally told to shut it.
Although the first spam message had already been sent via telegram in 1864, then it was send as commercial e-mail occurred in 1978, the term spam for this practice had not yet been applied in the 1980s. It was adopted to describe certain users who frequented BB (Bulletin board is a computer system running software that allows users to dial into the system over a phone line or Telnet), who would repeat “SPAM” a huge number of times to scroll other users’ text off the screen in early chat rooms services like the early days of AOL (Glasner, 2001).
Spam
Spam is considered to be an unsolicited commercial electronic message (figure 1). It is often a source of scams, computer viruses and offensive content that takes up valuable time and increases costs for consumers, business and governments (Cormack, 2007).
The Different Types of Spam
The most common spam is of course linked to spam emails. Nevertheless, there are different forms of spam:
Spam Voice Over IP
The spam VoIP also called SPIT or vishing SPLIT is a new kind of spam via the telephone and it's like Anonymous Call issued at any time of day or night, are issued to raise (as phishing technique) personal information (Saberi, 2007).
The Spam Messages in the Discussion Forums
This is an advertising message (containing commercial nature hyperlinks) left on some forums the goal is the same as the spam received by email: advertise for free (Saberi, 2007).
Spam in blogs (SIG):
It is called SPLOG (contraction of spam and blog). It is a very popular technique it's to let Internet users on blogs with links to advertising sites (Fumera, 2007).
Phishing
It is called filoutage or hameçonnage in french as presents the next figure 2. It is a technique by which attackers pose major corporations or financial institutions that are familiar by sending fraudulent e-mails. It retrieves passwords of bank accounts or credit card numbers. In this case the hacker could create a false social network page (Facebook, Twitter, ….etc.) appearance entirely legitimate. Then, when you try to connect the fake page, it saves your information with your user name and password in hand [A3].
Figure 2. A phishing model (Chirita2005)