3 Top Ways People Get Infected by An Email Virus

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Viruses are some of the oldest parasites known to humans. They probably evolved while the first cells started to populate the planet. With the invention of computers, witty programmers copied the properties of biological viruses and translated them into tiny computer programs.

The sole purpose of any virus is to replicate and spread itself. Damage to the host system is a potential consequence. The most common way for a virus to enter a computer is via email. So how do people get infected by an email virus?

Shouldn't everyone know how viruses enter a computer and be prepared? In this article I will explore the top 3 ways people get infected by an email virus and I will point out how you can avoid such a virus infection.

1. A Virus As An Email Hoax

As mentioned in the introduction, viruses typically are programs. But that's not always the case. Some viruses speculate on nothing but your naivety. Did you ever forward a chain letter, a virus warning, or the email of a desperate parent whose child needed an organ donation? You probably fell for a hoax and helped to spread it.

In this case the virus is the email itself, although it's not really an infection. The damage, however, is the same as with other viruses: clogging up of inboxes and mailservers. Email viruses generally cause a waste of time, resources, and energy.

Next time you receive a potential hoax email, don't forward it unless you're sure it's genuine. About.com features Top 10 lists of latest viruses, virus alerts, and virus hoaxes. Hoax-Slayer is a good resource to get informed about email hoaxes and eventually verify the credibility of an email you have received. Or if the email has tried to defraud you or steal your information, report it to the proper authorities.

2. A Virus In An Email Attachment

While forwarding an email doesn't cause you any major damage, an infection with a "real" computer virus, i.e. a self-replicating program, is a lot more critical. There are "harmless" variants that just forward themselves to your contacts. However, a virus may also be programmed for example, to destroy specific files on your system.

Most viruses are delivered through an email attachment. Attachments that contain viruses are either executable programs (file types: .com, .exe, .vbs, .zip, .scr, .dll, .pif, .js) or macro viruses (file types: .doc, .dot, .xls, .xlt). The safest way to avoid them is to not open email attachments.

Note that you can safely open Word documents in alternative programs that don't support macros, such as Wordpad or Open Office. Some viruses try to hide their true file extension by adding two of them. That's what the ILOVEYOU virus did; its name was "LOVE-LETTER-FOR-YOU.TXT.vbs".

The good news is that downloading and reading the email will not do you any harm. As long as the attachment is not opened, the virus won't hatch. If you don't know the sender and if the email text is suspicious, just delete the email along with the attachment.

If one of your contacts, however, was infected by a virus, the fraud is not as easy to spot. Carefully review each email and play it safe. Many web mail services can scan email attachments for viruses. If you use a desktop mail program like Thunderbird or Outlook and don't have a virus scanner that can scan email attachments, you may save (not open!) the attachment to your hard drive, where it becomes accessible for your virus scanner. Just remember never to open an attachment before it was scanned.

3. A Virus In The Email Body

Last but not least, malicious content can be found in the body of an email. Today, HTML is a common element of emails as it is used to embed pictures and links. However, HTML can also be used to embed scripts that execute automatically and subsequently infect your computer with a virus. That's why many mail programs, by default, block HTML and make you click a button to display content of trustworthy sources. It's a precaution you should not turn off.

Also, URLs can be a virus in disguise. You may see a harmless link that either leads you to a website that executes a malicious script or links to a completely different URL where you automatically download a self-executing virus.

Taken together, the same rule as for attachments applies: never view or access links from suspicious sources.

Summary

The reason why all these strategies work is because the respective email is cleverly designed to foul its recipients. It may be a harmless call for sympathy or a threat that calls for instant action. Most people will readily click any link that is presented to them in order to solve a problem or access further information.

What you can do is the following:

Act smart, not fast.
Verify the source of any suspicious email before you act.
Generally, do not blindly forward emails, open attachments and links, or view HTML content.
Get an antivirus program and regularly update its virus definitions.
Make sure your mail program is set to not automatically download and open attachments or display HTML content.

For more background information on viruses and malware, check out the following articles: