What Is Anti-Spam | Part 4

What Is Anti-Spam | Part 4

Filtering heuristics

Filtering heuristics testing message content (e.g., what proportion of HTML, images, references to pornography, acquiring easy money contain the rest of the message?; The subject is empty? The message identifier (message-ID) contain signs “dollar” (often used by software to send spam)). Each test gives a number of points (plus the total is lower, the better, unless the message is considered spam). The threshold point is arbitrary and defined by the system administrator who needs to find the score giving the best balance between the number of false positives and false negatives.


In the methods based Captcha, the sender of an email must prove his “humanity” by copying a word displayed as an image a captcha. A robot spammer will not know that word then copy a human can do very easily and will be allowed once for all to write to his correspondent.

Companies distributing solutions based captcha proclaim “a solution that eliminates 100% spam.”

The advantage of this solution is denied by official bodies responsible for developing and defining Internet standards. The Asrg (working group on spam IRTF – Internet Research Task Force) rather assigns a level of efficiency means a high level of nuisance and considers that this method has the same disadvantages of the methods called “Challenge-Response”.

Making emails paying

Putting a price on sending e-mails, symbolic items but legitimate deterrent for mass mailings (to 2 cents per post, it remains the same order of cost to the sender that a radio ad , yet it can be better targeted on the area where it was harvested address). And at 20 cents it will be necessary to put a franchise if it is access to sending mail to the individual in the tightest budget that begins to fade. One MP recently proposed taxing emails (0.005 cents) to fund the European Union.


In the Internet forums and Usenet and on mailing lists, are often used in moderation: a person of trust (“moderator”) reads the message whose publication is proposed, and eventually refused to broadcast (Moderation priori); or she reads the messages that have already been distributed, and deletes those that seem irrelevant (post-moderation). Since this method requires significant human resources, and more moderators are often accused (censorship) to the death, there is also a moderating robot (usually called “robo-moderation): Anyone can post a message through the robot, although this article has no interest (and even if it is actually a spam), but the robot does not leave the message that it responds to a simple criterion and known to all, as the presence of a certain word in its title.

This protection is particularly effective against spam that automatically broadcast identical messages in dozens of forums and have not been programmed to produce messages in accordance with specific requirements of any particular forum.

RPD (Recurrent Pattern Detection)

Technology RPD Recurrent Pattern Detection or “Detection of recurrent signatures” in French, is a technology that is based not on the content of emails, but their rate of spread across the Internet. With servers based around the world, it is possible to determine very quickly if an email is spam by verifying centrally the number of times the same email has been sent to the canvas. If for example the same email was sent to 100 000 copies at the same time, it will necessarily spam.

This technology provides a catch rate of over 98% spam for 1 false positive in 1 million. It is used for example by Cyberoam to fight against spam.

Fight judicial and legislative

In France, spam is regulated, especially since it involves the possession, storage (and often commercially available) lists of email addresses collected automatically (in discussion forums, websites), in contradiction with the law and freedoms.

Theoretically, a law requires the consent of recipients for all types of items containing the name of an individual. In practice, companies practicing this kind of business have answers ‘types’ to lessen the responsibility: either the user has clicked by mistake on a button (if you remember, it was a Thursday, 4 years ago) or he has not responded as it should have a question (you want to receive promotional offers from our partners or not, or may not know or I: Please answer YES or NO), see, the list has been rented to X or Y (necessarily unreachable).

In the United States, spam is regulated since 2003 by a law known as CAN-SPAM Act. It allows the spam, as long as the email subject is descriptive, as the shipping address is valid and a method of unsubscribing (link) is provided.

In many countries, no specific regulation is spam.

Several lawsuits have been initiated using existing laws:

•    If using a false return address and this address belongs to someone else, it can be seen as identity theft;
•    If it promotes an action of the stock exchange company, can be accused of practicing unlicensed stock brokerage;
•    If we continue to use a server after the owner has requested a court order for abandonment is the flight time of computer processor that may be prohibited by laws designed to stop further attacks against the computer systems;
•    If it is promoting medical products, there could be found guilty of practice pharmacist, doctor or nurse without a license;
•    Sending pornographic advertisements to mailboxes of children will not be a good idea;
•    If you commit other crimes such as fraud or sabotage web pages or computer sites, we may end up in prison;
•    Sending spam can be considered as theft and / or attempted intrusions into a computer system. This allows Chinese authorities to apply the death penalty against physical spammers.

Imprisonment is rare but it happens: Dave Rhodes, who sent such scams Ponzi or “pyramid” titled “Make Money Fast” in the early 1990s, found himself in jail for a few years, convicted of fraud.

The PRC has already sentenced to death and executed people whose only crime was sending spam. The legal basis used is the redefinition of the offense as a crime of espionage.

The most common lawsuits that have already held were costly civil litigation initiated by the big providers like AOL or Yahoo! against the most abusive spammers network, those who send millions of emails. Cyberpromo.com The site had to close its doors because of lawsuits like this and because of difficulties in finding a provider willing to provide Internet access to the such company.

As the problem is international, national laws have little effect on the volume of spam.

Finally, 2005 was a pivotal year in that the sentences were increased. Many spammers Americans have been arrested, convicted and imprisoned. Fines amounting to several tens or hundreds of thousands of dollars and prison sentences can reach more than a year.

Study: From Wikipedia, the free encyclopedia. The text is available under the Creative Commons.


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