Email spam is sending of unsolicited messages in bulk by email. Most email spam are commercial in nature. They are sent for the sake of advertising the business, service or products. But some of them are sent with an evil intent of inducing spyware or malware into the recipient’s systems and steal the information for various other crimes.
Emails spams that contain spyware can steal personal information of the recipient. This information can be used for stealing credit card information and secret numbers so that your money can be used to spend at their will.
Spammers usually get make a list of email addresses. They collect emails from various online and offline sources like websites, customer lists, customer database, feedback forms, newsgroups, etc. The collected list is often sold by agents to spammers for a good price.
Gary Thuerk was the first person to send email spam message in 1978 to 600 people. He was warned and told not to do it again. Currently, sending spam email is banned by the Terms of Service/Accepatable Use Policy (ToS/AUP) of the internet service providers (ISPs).
However, this kind of ban does not stop the incoming of unwanted emails. This happens because while visiting some websites, you need to enter your email id to get the information from that website. This entering of email automatically makes you give permission to the website to send “updates”.
Techniques used by spammers to fool spam filters:
Appending: When a marketer has a database of names, addresses and telephone numbers, he can use it to match against another database that has email addresses too. Thus, he obtains the database of email addresses by paying a small amount. He then uses these email addresses to send bulk messages, which look to the recipient like he is receiving from a particular company.
Image spam: In image spam, the text content is stored in the form of image so that the spam filters do not detect and block it. Often the text in the image contains nonsensical content that is annoying to the reader as the content is computer-generated. Some techniques use GIF images that are not even clear or use symbols and contorted shapes of letters to escape the filters of optical character recognition tools.
Blank spam: The body or content of the email may seem to be missing, yet this unsolicited email has been sent in bulk. It may happen due to various reasons. The spammer may have forgotten to include the subject and content of the email. Poorly written spam message or malfunctioning relay servers or software bugs may truncate the header lines from the message body. Blank spam might be sent deliberately to use the bounces to eliminate the invalid addresses in the spammer’s list. But the worst that could happen in blank spam is that it actually may contain a virus or spyware that grabs the HTML code to download other important files from the website or user’s system.
Backscatter spam: Backscatter happens when the email servers are misconfigured to send a false bounce message to the sender when rejecting or quarantining email.
Email spam is usually annoying to the user of a website. Spammers can take over your website through various means and send email spam from your website. This can have adverse consequences to your business. It is important that you check and clear the entries of such unwarranted spammers and hackers.
