What Is Malware? Definition, Types, Removal Process, and Protection Best Practices

Malware is defined as any code packaged as a software application, designed to cause harm to a standalone computing system (PC, laptop, smartphone, tablet, IoT endpoint), a server, or an entire network of connected systems. This article explains what is malware and shares malware removal best practices for your operating environment to help you stay a step ahead of hackers in this digitally connected world. 

Table of Contents

• What Is Malware?
• Types of Malware
• Malware Removal Process
• Top 8 Best Practices for Protection Against Malware in 2021

What Is Malware?

Malware is defined as any software designed to damage, disrupt or infiltrate a standalone file, computing system,  server, or an entire network of connected systems.

Malware may also be created and deployed with the intention of locking the user out of a system or file and drawing a ransom in exchange for the passcode. In certain cases, malware may simply cripple your system without benefitting its source. 

Malware continues to pose a great risk to individual and enterprise security. It is no wonder then that the malware analysis market is expected to reach $16 billion by 2025Opens a new window . By following best practices and taking appropriate malware removal measures, you can retain control of your vital systems and stay safe.

Malware is always intentional, a key differentiator from a software bug. A software bug might cause accidental vulnerabilities, like the unintentional security flaws in Zoom is looking to address with its 90-day plan. 

Large-scale work from home (WFH) has blurred the lines between personal and professional device usage. Unfortunately, this exposes computing systems to a wide range of vulnerabilities, including malware. Let’s say you have your work and personal email clients open side by side. Your inbox might show a promotional mailer, but clicking on it installs malicious software (or malware) in your system. This software then works in the background, collecting data or infecting your systems. 

It’s no surprise that the number of ransomware attacks (a type of malware) increased by 148%Opens a new window during COVID-19. So, how do you stay vigilant and ensure a safe computing experience that protects users against malware? The first step is to understand the concept of malware. To sum up, malware is a dangerous piece of software intentionally designed to either profit or cause undue harm.

How does malware work?

A malware may explore several vulnerabilities that allow it to enter your computing environment, stay concealed, and continue to cause damage without any visible indication. For example, there might be software available which claims to do something harmless – like help to download Youtube videos. But once you install it, it sits inside your system, waiting to trigger an attack on a specific date or time. 

Malware often works like a contagious infection. Once there’s one harmful software installed, it opens up gateways or “backdoors” that allow other malicious software to enter your system without the requisite authentications. 

Once it is installed, the malware might do one of the following: 

• Try to capture personal information like financial details, credentials for online banking, etc. 
• Target a corporate user to get information linked to work – this might get a malware designer/distributor access to large pools of customer data and other sensitive information. 
• Simply sit in the background and slow down a system – such apps are considered as “grayware” as they pose a less severe threat than regular malware. 
• Push unwanted ads to the user, earning revenues through malicious means. 
• Hand over full control of your systems to a remote operator. 

One of the recent malware trends is the rise of ransomware, where a remote operator blocks access to specific system functionalities until the user pays a certain amount. Let’s discuss ransomware and other types of malware in detail. 

Also Read: What Is Ransomware Attack? Definition, Types, Examples, and Best Practices for Prevention and Removal

Types of Malware

The list of malware types (or the range of cybersecurity threats in general) is growing every day. As recently as July 2020, reports emergedOpens a new window about a new variant called “shadow attack,” which forges key documents. In this type of security attack, threat actors can alter the contents of a digitally signed PDF document and lull users into a sense of security. Let’s look at the different types of malware:

1. Ransomware

Ransomware blocks a user’s access into a system or data file and refuses to open it until payment in the form of a ransom is made by the user or organization where the user is employed. It might block a computer’s sign-on screen, or go to the extent of encrypting large volumes of important information and hold it “hostage.” The WannaCry ransomware attack of 2017 brought this particular malware type to the forefront of global conversations.

2. Virus

While the terms “virus” and “malware” are often used interchangeably, a virus is actually a highly specific type of malware. A virus refers to any application that alters the code or structure of a target file or software. Like a biological virus, it attaches itself to a legitimate software (called the host) and slowly disarms its functionality. 

3. Trojans

Like the Trojan horse from Homer’s Odyssey, a computer Trojan is malware masquerading as a legitimate app. This type of malware has become surprisingly popular over the last few years owing to the rising online traffic and interest in downloading applications (safe or otherwise). In Q1 of 2019 alone, Kaspersky detected over 29,000 installation packages for mobile banking Trojans. 

Also Read: Top 10 Malware Scanners and Removers in 2021

4. Adware

Adware is among the most common malware types. Its goal is to route a user to an unwanted piece of advertising, hoping to gain some revenues. Adware often comes bundled with legitimate software programs that are downloadable off the internet. A more stealthy variant would be an adware that directs you to a familiar-looking website (e.g., an Amazon shopping window) but contains a series of unwanted ads. 

5. Worm

Just as the name suggests, worm refers to a self-replicating type of malware, which quickly spreads across your system and to other computers via a connected network. Unlike a virus that needs someone to use the host application, a worm has very little dependence on human action. This makes it more effective and dangerous than a typical virus. Worm attacks usually work in the background, slowly spread across the network, and make its presence felt only when it’s too late. 

6. Mobile malware

Mobile malware is different in structure, as it targets a different operating environment. For example, banking Trojans are a common malware type for mobile phones, as users are likely to trust a bank provider without conducting due diligence. A new mobile malware called LeifAccess was discovered last year. This malware installs itself on your smartphone, creates multiple accounts, downloads apps, and posts reviews, turning your smartphone into a review farm. 

7. Spyware

Spyware comes in different shapes and sizes. Some spyware falls into the category of keyloggers, which monitor your keystrokes to gather sensitive intel like passwords, pin numbers, proprietary information, etc. Others can take over computer peripherals like a webcam to record videos of the user’s surroundings or listen-in using the mic. Some spyware can record your browsing history and online behavior to push more targeted adware (see point 4). 

Also Read: Top 10 Malware Protection Software in 2021

8. Malicious bots

A bot is a highly flexible type of malware that can auto-execute commands at a certain date or time. They are also called botnets, and interestingly, they aren’t always malicious in nature. In the computing world, bots perform several legitimate activities, such as automatically indexing websites for search engine results. 

However, a threat actor could use this in a malicious way. For example, it could install the same bot in thousands of systems and program them to log into a specific website at the same time. This floods the website beyond capacity, ultimately crashing it. Bots can turn a computer system into an attack accessory, not necessarily the target. 

9. Rootkit

A rootkit is designed to give a remote threat actor unauthorized access to privileged systems/restricted software. Typically, a rootkit doesn’t work as a standalone malware. Instead, it enters your system as a suite of different tools, including keyloggers, spyware, bots, etc., all working towards a single goal. 

10. Malvertising

Often, a legitimate ad platform is used to direct users to a fraudulent/malicious website. Let’s say that you have downloaded a new, freely available PDF reader. If the app is ad-sponsored, there is a good chance that you will see unverified and untargeted advertising content. Clicking on these will lead you to a harmful website, where any activity will further expose your system.

11. Fileless malware

It might seem that malware always comes in the form of a visible, tangible file, but that’s not the case. Fileless malware can exploit your systems using other objects like an API, PowerShell tools, or a Windows registry key, without leaving a visible software footprint. These apps don’t rely on user downloads or installation — rather, they piggyback on legitimate programs, blending with your natural computing environment. 

12. Hybrids

This type of malware uses a hybrid approach to attack a system. For example, a virus sends unwanted advertising content like adware, or a fileless malware spreads like a worm. Some malware attacks have also been known to morph in different stages – it could initially seem to be a Trojan, but morph into a bot, allowing the attacker to control the system. That is why it is so important to be conversant with the different types of malware and their definitions, to plan out a route for tackling them. 

Also Read: What Is Malware Analysis? Definition, Types, Stages, and Best Practices

Malware Removal Process

Malware can cause untold damage if left alone to run in the system background. Therefore, it’s crucial to stay vigilant and nip the problem in the bud. If a system is performing worse than usual, if specific functionalities are slowing down, or you are unable to access an important feature, it might be because of hidden malware. 

So, how do you remove these dangerous applications, working around theory various modes of concealment? Is there a process you can follow for effective malware removal? 

Let’s dive into the various ways to remove malware on Windows, Mac, and Android systems: 

1. Malware removal for Windows PCs

Windows is among the top operating environments hit by malware for two reasons. First, because a majority of PCs around the world use Windows, it is a convenient target for threat actors. Second, because Windows doesn’t come with the same, stringent security protocol as Mac. If you’ve noticed a Windows system performing unusually, follow these steps to detect and remove malware: 

• Create a checklist of possible malware indicators

Watch out for malware indicators like:

1. A slow boot-up process
2. Unexpected pop-ups
3. Difficulty in accessing a frequently retrieved website
4. A new app on the staff menu that you don’t remember downloading
5. Shrinking hard disk space without proper justification
6. Compromised hardware behavior like low-quality sound or display

A checklist like this will help you regularize malware removal and not leave it until the very last moment. 

• Start the PC in safe mode

Most types of malware enter, spread, and act via the internet. In safe mode, all the apps that would automatically initiate at bootup are terminated. This lets you assess genuine Windows speed and the number of apps you might be dealing with. 

Also, safe mode without networking prevents the system from accessing the internet, rendering the malware powerless as you explore removal routes. There are several ways to enter the safe mode – you could either troubleshoot from settings, restart to safe mode from the sign-in screen, or switch to safe mode if you face a blank/black screen. 

• Optimize disk space before running a malware scan

This step ensures that your system has the maximum amount of resources as it hunts for malware. Search for the Disk Cleanup utility on Windows from the search bar on the bottom of your desktop. You can clear temporary files that are taking up disk space from this utility. 

• Scan your system for malware

There are two ways to do this. You can use a third-party provided antivirus or cybersecurity solution to analyze your system for traces of malware. Alternatively, you can use Windows’ built-in utility called virus and threat protection. Typically, it runs in the background, checking for different types of malware at regular intervals – but you can also choose the Quick Scan option for an on-demand check. 

• Decide on your malware removal action

Once the scan reveals malware, you have three options: do nothing, send it to quarantine, or delete the file altogether. The decision will depend on the nature of the file, and the severity of the attack. For instance, a pure virus attack can be tackled only via deletion, as the host is already infected. But for other types of malware like adware, you might want to keep it in quarantine. 

Also Read: What Is Social Engineering? Definition, Types, Techniques of Attacks, Impact, and Trends

2. Malware removal for Mac

For a long time, it was assumed that macOS was inherently resilient to malware, thanks to the sheer nature of its system architecture. But that’s no longer the case. In the last few quarters, malware attacks on Mac have been trending upwards, with a frequency of 9.8 detections per device according to one provider, in contrast to Windows’ frequency of 4.2. 

Expectedly, malware removal on Mac follows a different process than Windows. Here are the steps: 

• Find apps taking up disproportionate resource volumes

From the Launchpad, open the Activity Manager to assess how different apps and processes are performing. Here, you might find a malicious software working in the background, taking up a lot of memory or constantly interacting with the network. Immediately quit the process from the Activity Monitor, and then move the app to your Trash, to remove the suspected malware. 

• Conduct a quick search for .DMG files

DMG files are essentially containers for different applications in macOS. Threat actors will often insert an executable .DMG file into a harmless download, like a video or an audio clip. Keep an eye out for this potential malware indicator in your Downloads folder. 

• Avoid any pop-ups in your browser

Pop-ups are a common way of distributing malware. Fortunately, it is easy to block them. Chrome comes with built-in pop-up blockers, and if you’re using Safari on Mac, navigate to the Security option on the Safari preferences menu. Check the “Block pop-up windows” option to protect your system against possible malware. 

• Disable suspicious apps from your login items

Most malware start-up with the computer system. They weave themselves into the bootup cycle, initializing with the rest of your legitimate applications. You can weed out such types of malware from the System Preferences utility. From the Apple menu, open System Preferences and navigate to the Users & Groups section. Select the admin username and click the login items tab. This will list all apps that auto-initialize and bootup. Ensure that you hide any suspicious app and save. 

Also Read: What Does Colonial Pipeline’s Ransom Payment Mean for the IT Industry?

3. Malware removal process for Android

Android has the biggest smartphone market share in the world in 2021.  85.4%Opens a new window of smartphone users have an Android device, with only 14.6% falling to iOS. As a result, malware designed for Android will have a wide reach, necessitating appropriate defense mechanisms. Here are the steps to remove malware on Android: 

• Look out for telltale signs of infection

It’s relatively easy to understand if malware has entered an Android phone – the battery will deplete faster than usual, RAM will be occupied despite no apps being open, data usage shoots up, and carrier bills could also rise. If you spot any of these symptoms, don’t put them on the backburner. 

• Download Google Play Protect

Recognizing the growing threat of Android malware, Google has come out with a dedicated app to tackle the problem. Simply open the Play Store on your smartphone or tablet, and run a device status check. Google Play Protect comes built-in with your Android device and is turned on by default. This is an easy way to check for and remove Android malware. 

• Use your smartphone in safe mode

Just like a Windows PC, Android systems also come with a safe – or emergency – mode. To turn it on, press the power button (or the power icon on the top of your notifications screen) until you see the Power Off and Restart options. The emergency mode is turned off by default – you can switch it on after accepting the terms and conditions. Using a smartphone in safe mode prevents the malware from causing any further damage. 

• Report suspicious app activity

Unlike iOS, Android doesn’t prevent users from downloading apps from outside the Play Store. 

It offers a useful feature that lets you report any suspicious apps you might have downloaded to Google. Activate this from the Play Store – Go to Play Protect on the left menu, open the Settings menu on the top right, and turn the “Improve harmful app detection” toggle on. 

Also Read: Ransomware Payments: Is Cyber Insurance With Proper Controls the Best Solution?

Top 8 Best Practices for Protection Against Malware in 2021

It is much easier to protect your system from malware than it is to remove it. In drastic scenarios, you might lose important files or even the device itself due to the infection. Here are some best practices to follow for malware protection. 

1. When browsing the internet, avoid any suspicious links

Avoid downloading or clicking on any site link of an unknown brand site or a fake URL, insecure site or a suspicious email that asks you to download something or click a link.

For example, if a hacker might purchase a site named coca-cola.net when the actual site for the Coca Cola brand is coca-cola.com. Many users may miss this small change in the URL or ignore the browser’s prompt and click on a link on the site that carries an infection code.

2. Develop internal spam filters, in addition to the ones enabled by your email client 

Most email clients (Gmail, Outlook, etc.) come with built-in spam filters, scanning email content for known red flags. But sometimes, an email could circumvent these filters using a clever ruse — for example, using “COVID-19” in the subject line to appear as urgent, official communication. Users need an attitude marked by scepticism and rational suspicion to tackle this, making sure to not respond to unfamiliar senders, pleas for financial help, or vague content. 

3. Set strong passwords and change them regularly

Avoid using personally identifiable information, such as phone numbers or birth date as passwords, as these are easy to crack. 

4. Activate your built-in security systems

Most devices, including Windows and Android, come with pre-built malware protection, which shouldn’t be turned off. Run regular scans so that malware doesn’t reveal itself only after it has started to spread. Daily scans are recommended for power users, working with confidential or valuable data. 

Also Read: 6 Tell-Tale Signs of APT Attacks To Watch Out for in 2021

5. Use a paid malware removal tool

It is among the most effective ways to add an extra layer of malware protection, over and above your pre-built security mechanisms. 

6. Don’t share login credentials with anyone or save them online

By keeping your login credentials closely guarded, you minimize the risk of a family member exposing your accounts to vulnerabilities. Moreover, it is better to not save them online either, as that makes your details more vulnerable to hackers. For example, a hack on the software you are using (say a note keeper app) may reveal all its contents, including passwords and login IDs. This leaves you vulnerable to even more hacks.

7. Create a restore point for when you have a clean system

This will let you rollback infected systems to a time when it was absolutely clean, using the restore point as a backup. 

8. Stay informed

Malware and its methods of deployment are constantly evolving and improving – just like malware security systems. What is key for any user is to stay informed and vigilant – after all, most malware requires user action in some form or another to gain access.

Have you successfully identified and removed malware in the past? Comment and let us know on LinkedInOpens a new window , TwitterOpens a new window , or FacebookOpens a new window . We would love to hear about your experience.