Malware 101- Understanding the Basics and Protecting Your PC

Andrew Sanders
Posted: April 8, 2019

If you don’t know what a computer virus is, or haven’t been infected by one before, then you might not know the signs to look out for. People often think that a malware infection looks like something out of a fanciful movie – flashing lights, smoke coming out of your computer tower, a laughing skull appearing on your monitor.

In truth malware infections are much subtler – and therefore much more frightening – than the representations you may have seen before. By the time you realize that your computer is infected with malware, attackers may have already emptied your bank account or stolen your identity. Defending yourself from malware means understanding the basic definition of malicious software and what it’s capable of.

Malware Definitions

At its heart, malware is any computer program designed to install itself on your computer and change files there without your permission.

This definition neatly encompasses nearly any kind of malware you can imagine, from fairly benign adware to extremely malicious ransomware and rootkits.

Malware 101- Understanding the Basics and Protecting Your PC

A detailed explanation of how malware infiltrates a computer

In addition, most if not all of these attacks seek to monetize the user in some way unbeknownst to them. Adware hijacks your browser and allows websites to target advertisements to you. Spyware steals users’ login information in an attempt to monetize them by draining drain their bank accounts. Ransomware monetizes the user by encrypting their data and forcing them to pay for technical support.

Lastly, most if not all of these programs are designed to do their work without your knowledge. Even ransomware – which makes a definite point of letting you know you’ve been infected – performs most of its actions covertly. The part of the virus that encrypts your computer and displays a ransom note is just the tip of the iceberg.

These three elements – changes to your computer without permission, monetizing your data or your behavior, and doing it without your knowledge – help pin down a broad definition of malware.

Glossary of Malware

Malware comes in a huge variety of flavors that lie underneath the broad definition of malware that we’ve established. Here are some to look out for:

  • Virus
    Not all malware is a computer virus. Viruses are designed to trick people into opening them, and they then infect legitimate files. Ironically, many anti-virus programs struggle to remove these programs – instead, they simply quarantine and delete the file.
  • Adware
    Infects your browser, usually via a drive-by-download, and causes your browser to display specific targeted advertisements.
  • Trojans
    Malware designed to mimic legitimate programs or files in order to disguise a viral payload. Some are based off helpdesk software, such as Teamviewer, that lets administrators remotely troubleshoot computers. These are known as Remote Access Trojans (RATs). There are also banking Trojans, rootkit Trojans, backdoor Trojans, and more. They are the most commonly-deployed virus that you’ll see in the wild today.
  • Ransomware
    Most ransomware is also – surprise! – a kind of Trojan. Ransomware files are commonly disguised as Word documents, slide decks, or PDFs. Once opened, sophisticated forms of ransomware will inventory your system, finding the areas that will cause you the most inconvenience when decrypted. This can include backups you’ve made of your hard drive and important files.

What we learn from this glossary is interesting. Essentially, the wider malware community has moved on from what’s traditionally considered a “virus.” According to some estimates, traditional computer viruses now make up only ten percent of all malware. Trojans comprise most of the rest, with even the vast ransomware family making up a subcategory of Trojan malware.

Defending Yourself from Malware

It is much easier to prevent yourself from being attacked that it is to recover from a cyberattack. You can prevent attackers from installing malware on a home computer by using basic antivirus software, which is often available for free. By contrast, removing a virus from your system usually means finding the exact kind of malware you’re dealing with, finding a tutorial to remove the virus, and then pursuing a complicated checklist that involves aspects of your computer which home users aren’t likely to be familiar with (i.e. editing registry keys).

In the end, you’ll probably just have to re-image your computer anyway.

If you’d rather avoid learning first-hand what malware can do to your computer, then your next step is simple – find a decent antivirus! Check out our list of top ten antivirus programs and download one today!

About the Author

Andrew Sanders
Andrew Sanders

Andrew is a writer on technology, information security, telecommunications, and more