4 Types of Malware You Must Avoid

Trojans, spyware, worms and viruses are types of malware designed to cause people trouble.


You may find yourself overwhelmed these days with the quantity of technical computer terms in ordinary news reports. After all, what with so many companies and governments getting hacked, online security is front-page news on a regular basis.

To help you keep abreast of the lingo, we’ve compiled a short glossary of some malware types that you may have read about lately. So if anyone says “What the heck is the difference between a Trojan and a virus?” at your next weekend BBQ, you’ll have an answer.


Trojans – The Art of Decoy

This type of malware, which gets its name from ancient Greek mythology, was named after a large wooden horse that secretly housed Greek soldiers. The Trojans thought the horse was a gift, so they pulled it towards their town, but in the dark of night, Greek soldiers came out of the horse and attacked the city of Troy.

Modern Trojans operate under a similar principle. They are a form of malware disguised as useful programs, or hidden inside of useful programs. Trojans are usually installed on people’s computers through trickery. A person receives a file or attachment, thinks it is legitimate, and downloads or installs it. Then, in the dark of night (or in broad daylight) the Trojan springs into action, deleting files, destroying information, and/or allowing outsiders to gain access and control the computer. Trojans do not reproduce or infect other files, and they do not replicate themselves.

Worms – The Silent Danger

This type of malware is a standalone program that can be spread through emails or over networks. Worms are often disguised as attachments, or hidden inside attachments. When an infected attachment is opened, the worm is installed. Once a worm is on your computer, it can spread in a variety of ways, such as emailing itself to an address in your address book or searching your hard drive for email addresses. Worms can also open backdoors on your computer (which can allow remote access to hackers), and enable your computer to be used for a Denial of Service (DoS) attack.

Worms don’t need to attach themselves to existing programs, and they can travel from one computer to another without any human action. Worms can replicate themselves on your computer and then send out hundreds (or thousands!) of copies of themselves. If a worm replicates itself and sends itself to others (for example, all the people on your email contact list) then it can infect every one of those computers if it is opened.

Spyware – Just Like it Sounds

This type of malware includes any type of program that spies on a person’s computer activities. Spyware may gather personal information such as usernames, passwords, or account numbers. It may track which websites you visit and what emails you write and receive. Spyware is usually installed unknowingly along with a product that was deliberately installed. The information gathered by Spyware is often used for advertising purposes but that doesn’t mean the consequences aren’t serious. Spyware can make changes to your computer and cause it to slowdown or crash.

Viruses – More than Just a Sore Throat

This type of malware gets its name because it has many of the same traits as a biological virus. Viruses pass from one computer to another, much like biological viruses pass from one person to another. Computer viruses cannot reproduce on their own; like biological viruses, they need a host (i.e., a program or document) to do so. Viruses must be actively launched in order to cause trouble.

The Art of Avoiding

Of course, just because you’re on a first-name basis with these threats, doesn’t mean you don’t need to be vigilant to keep them off your computer. Here are some tips to keep in mind in order to protect your PC from these (and other) threats.

1. Install a top-grade antivirus like ZoneAlarm Extreme that protects you from both known and unknown threats.

2. Make sure your operating system is updated, and only use updated browsers, too. Updates often contain patches that have been implemented to fix potential security risks.

3. Use common sense when you are online. If a site you visit looks sketchy; surf elsewhere. If an unexpected email comes with an attachment, don’t open it.

4. Think twice before using public WiFi. If you connect your laptop to the internet via public WiFi, you could be exposing all of its data to hackers using the same WiFi.


Have you ever encountered any of these types of malware? 

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