Spamming
Spamming is a method or perhaps a malicious activity of using the messaging system to send mass mailing to advertise about something or the other, which the recipient never had looked or searched for. In short, they are unsolicited mail.
There is a huge scam that comes to picture about the mails having the information about someone clamming to be a family member of a deceased person and is willing to relocate, or some government personnel asking for bank details for sending you the money, this was classified as Nigerian scam.. In this, the money is robbed from the account as soon as they receive your bank information.
Types of Spam:There are variety of categorization for the SPAM and these categories are increasing.. Not all but half of the them are like financial email, education and training, Adult URLs in it or Adult contents, some related to the health products, and some being virus.
1.) Financial categoryMail with description about low interest on loan, investments with high returns, insurance, etc. 1 out of 100 or may be 1000 or more falls for this as the need arise for the individual.. However, these are not true information (Unless properly checked for) and you may end up giving some of your personal financial information.
2.) Educations and Training Mails with contents full of information related to the courses offered, university information, their advertisement on various training and online seminars. This is considered to be an educational fraud and individual is directed towards a fake university degree.
3.) Adult Contents This is perhaps the biggest one in the Spam category. These type of mails usually contains product related to sexual health, links to the pornographic websites, some adult products.
4.) Virus Mail An email is send with a document attached, and when this attachment is opened, it starts spreading by forwarding mails to multiple recipients and groups in your email address book. There may be incident when a spamming is occurred through a email client configured and this is the one that triggers it without the user knowing it.. Be Careful before you open an attachment.
There are lot of them and they all are categorized according to their behavior.
How does it work? Spammer sends this type of mails to obtain valid email addresses as much as possible.. They use different techniques for this:
a.) They may get this by purchasing a database from a advertising companies that they already have with thousands and millions of email accounts already with them.
b.) Spamming can directly attack to get the information about email address, i.e., Directory Harvest Attack, in this the spammer creates an email address that belongs to specific domain and send messages. The domain mail server will respond to it stating it is valid email address or not and he can track the one those are valid.. To do this, he may have some script that will do a compilcation of different combination or words as email user for the domain, like a brute force.
Technique used 1.) Use of null characters those are encoded
2.) Use of interchangeable letters to bypass the spam filter, so if name "Viagra" is blocked, it will use "Vaigra" and the spam filter will not catch it.
3.) Hiding the malicious link under legitimate tag, encapsulating it with tag "herf" in HTML.
4.) Using ASCII design. Group of symbols or letter that meant something in design, but individually it means nothing.
What methods do they use? 1.) They may target vulnerable mail servers (open relay), which may allow users to send message without verifying it.
2.) Computers affected with malware, as discussed in the different types of spam section.
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