What Is Malware? Identify and Prevent Attacks

The threat of malware seems ever-present for Internet users. Whether it's due to a suspicious website, a shady email link, or even a computer on your network spreading an infection, malware attacks can happen anywhere. But what is malware? It's crucial to be aware of how it works, how it can appear, and how to protect your devices and your information as best as possible.

What is malware?

Malware is the short term for "malicious software." As the name implies, it's any kind of program that seeks to harm a system or individual through technological means. It seeks to invade or take over a device's operations in order to stop normal functions, cause corruption, steal information, and more.

Depending on the type of malware, it can spy on your computers or mobile devices, take your data or files hostage, delete your data, or slow down the device. It doesn't affect a device physically, but it can destroy your device technically, rendering it unusable.

The software often installs unknowingly on a system that tracks data about the system and users. The system and users can even make unwanted or unknown changes to the computer's settings.

Six types of malware to watch for

Because malware comes in so many different forms, it's important to recognize the ways it could appear on your device. Below are the six most common types of malware attack and how they operate.


Computer viruses, just like real-life viruses, have a knack for spreading. They work by sneaking onto your device and infecting a program or file on your device. Then, they travel from device to device, using shared networks, files, and documents as highways.

The danger in viruses is that they can corrupt files and even cause whole systems to crash. Viruses can do many things once they've infected your computer. For example, the virus might have been designed to collect the personal information held in your files.

Viruses can be very difficult to eliminate as they infect many files on a computer. You can delete an infected file without getting rid of the virus, as it may have already infected many other files on your device. Because of how tricky viruses are, proactively getting strong antivirus software is crucial to protecting your device and your files. 


A worm is like a virus on steroids. Viruses require some sort of user action, either downloading a file or opening an email. Worms, on the other hand, require no action on the part of the user. Worms can infect files and systems completely on their own; they let the files and programs spread the malware themselves.

Thus, a single action by one user, such as downloading an attachment, can cause a super-spreading event. That leads to compromised whole networks or systems in a matter of minutes.

Trojan horses

A Trojan horse virus, also known simply as a Trojan, is a type of malware that infects your device by tricking you into downloading something. We are often warned not to download unknown files or open emails from unknown senders; this is to avoid Trojans.

Trojans are named for the Trojan horse of the Trojan war, and aptly so; they present themselves in the same hidden way that the people of Greece did during the actual historical event. Trojans show themselves as legitimate even though they're a front for a virus. For example, a Trojan might appear as an email instructing a user to update his or her antivirus software. If the user clicks the download button, their system will become infected, not healed.

Trojans are capable of stealing information you provide online, including your passwords and credit card information.

Hybrid malware

The hybrid malware attack can include methods from more than one type of malware. For example, a piece of malware can be a trojan, a traditional virus, and a worm all at the same time.

Because hybrids are made up of different types of malware, they can be especially difficult to ward off.


Spyware is a type of malware that allows hackers to see what you're doing on your device, or to see what is happening on your system. This makes it quite easy for hackers to steal your personal information, such as passwords, credit card information, and intellectual property. Additionally, this spyware obviously used to spy on your browsing activities - exactly which sites you're visiting and when. Keyloggers, for example, are a form of spyware that logs each keystroke you type into your computer, giving hackers access to everything from your emails to your passwords to your Google searches.

A spyware infection can change your Windows registry, which causes systems to slow down and creates errors, among other problems. Spyware programs can also take up memory space, and because computers have a very restricted amount of secondary storage memory, this can also slow a system down. It also bogs down a system's CPU by taking processing time. It can be difficult to remove spyware because the victim is often unaware of its presence entirely.


Ransomware attacks encrypt all of the files on a system or network, then require a ransom to "open" to files again. This is typically done against large organizations, such as city or state governments.  Hackers ensure retrieval of the ransom by threatening to permanently delete all of the files if the ransom is not received.

Ransomware is one of the most costly forms of malware. This is because organizations typically cannot afford not to pay the ransom. The files can be crucial for the proper functioning of the organization. Also, paying the ransom does not ensure that the files will be unencrypted; hackers are criminal by nature, and they still may decide to delete the files anyway.

Signs of malware

There are several signs that may indicate malware installation on your computer. These are not all of the indicators of malware, but they're good indicators of a problem. Be wary if:

  • A large number of advertisement pop-ups appear very frequently every time you browse the web. This happens even without opening the browser.
  • There are bookmarks, favorites, toolbars, search-bar or other components that appear on your browser. These are things that you did not install or previously set.
  • The browser goes to company websites, affiliate pages or pages other than your normal homepage as soon as you open your browser.
  • You notice changes made to your browser or system setting.
  • Your computer is generally running slower on start-up, program operation, or overall.

Malware protection

There are a number of programs that you may use to find spyware and adware on your system.  However, like a computer virus, it's much better to prevent spyware than to clean it from your system. The following is a list of tips that should help you prevent your system from falling victim to spyware and losing sensitive data.

  • When installing shareware or freeware programs, always read in the terms of use policy before agreeing. The terms should warn users of any software that contains adware.
  • Keep your operating system as up to date as possible. Setting up automatic updates helps users stay on top of their malware protection. Don't forget to also update your operating system and other software regularly. Software and system updates usually contain security patches to better protect your device from attack.
  • Be careful where you browse and try to stay away from suspicious sites or sites. Similarly, be careful where you download files and only install software from reputable companies and sites.
  • Make sure that you have a firewall set up to protect your computer and network. In your browser, configure the browser security settings for maximum protection and security.
  • Avoid free Wi-Fi if you can, as it's easier for hackers to gain access to your device on it than on a private network. If you can't avoid free WiFi, consider using a VPN to protect your connection and encrypt your network traffic.
  • Think before you click. If an email prompts you to open an email attachment or click a website, contact whoever sent you the email and ask them what it is first. Hackers often disguise malicious links in deceptively normal emails.

Free anti-malware software

There is a multitude of choices when it comes to anti-spyware software. Many companies offer free software downloads for users to protect their systems at no cost. If a free program is what you're after, we recommend Ad-Aware Free, which allows for you to schedule daily antivirus scans with real-time security updates. Spybot Search & Destroy and Microsoft Security Essentials are also great programs if you want to save money and still protect your devices.

Though free anti-spyware software works, we have found that the paid versions of anti-spyware and antivirus programs are better.  They actually offer better all-around security, detection and protection.

For best overall coverage, AVG Internet Security has a great security package for only a few dollars a month. They offer a free version as well, but their Ultimate version provides the best protection. You also get access to their VPN and anti-tracking services.

ESET Smart Security is another great option. In addition to excellent antivirus protection, the program provides its own password manager for users and free photo encryption. PC Tools Spyware Doctor works well as a base program to spot and eliminate all kinds of malware, including spyware, Trojans, adware, and keyloggers.