What is malware?
Malware is malicious software designed to harm, exploit, or gain unauthorized access to devices and data.
What is the purpose of malware?
How malware spreads
How does malware infect your devices? Here are a few of the most common ways that could happen:
The most popular method of spreading viruses is through email. Both simple spam and sophisticated phishing attacks still trick people into clicking on links or downloading attachments that contain malware.
Careless browsing
If you click on any pop-up or advert that you come across while browsing, chances are, you’ll eventually end up on a malicious website. It might download malware in the background, and just like that, you’ll have a keylogger or a trojan on your device.
Coworkers
Some malware spreads through the internal network. For example, someone forgot their cybersecurity training, clicked on a malicious link, and the next day, everyone’s computers are encrypted, with no access to their accounts.
Bundled software
Malware is known for piggybacking. So even when you download a trustworthy piece of software, you might install adware or spyware together with it without even noticing — until it steals your banking data.
How do I know if I’ve been infected with malware?
Familiarize yourself with the most common signs of malware so you know when something is wrong and it’s time to act.
How malware affects different devices
Malware can impact devices differently based on their operating systems and inherent vulnerabilities.
While macOS is often perceived as more secure than other platforms, it is not immune to malware. Adware and potentially unwanted programs (PUPs) are particularly prevalent on Macs, with more advanced malware, like ransomware and spyware, also growing in popularity. Users are most at risk when they download software from outside the App Store, use outdated apps with unpatched vulnerabilities, or postpone important OS updates.
Malware on Windows, due to its widespread use, is diverse and abundant. Ransomware, trojans, and worms are some of the most popular, meant to encrypt user data for ransom, steal sensitive information, or self-propagate to other systems. Many PC users infect their devices by opening and executing malicious email attachments, downloading and installing unknown software, or using outdated apps and OS.
Android is a relatively open platform with many third-party app stores offering an array of apps for various purposes. The most widespread threats include rogue apps disguised as legitimate ones, SMS-based malware that covertly subscribes users to premium services, and banking trojans meant to steal your bank credentials.
iOS is a closed ecosystem with a very strict app review process, so malware is less common — but iPhones are not invincible. Cybercriminals mostly target jailbroken devices, infecting them through malicious apps from unofficial app stores. Some have found a way to install new user profiles on iPhones and take over control of the device. Infected iOS devices drain their batteries very quickly, apps crash often, and users may notice a significant increase in data usage.
How to remove malware
There’s no universal solution. Malware removal depends on many factors: the operating system, the specific malware that infected it, whether you need to save your files or not, and so on. You will likely need to buy an advanced and trustworthy antivirus software to scan your device and delete any malware that’s on it. And it still might not work — for example, more advanced ransomware is likely to be impossible to remove.
Read our blog post for more detailed tips on how to remove malware.
How to protect yourself from malware
Here’s how you prevent a malware attack:
Types of malware and malicious attacks
There are countless varieties out there, so we’ll stick to some of the most widespread malware examples. Here are the top most common types of malware:
Adware is a relatively innocuous type of malicious software that focuses on making money rather than harming your computer. This aggressive advertising-supported software displays banner advertisements on websites and application windows.
Symptoms may vary, but the main one will be pop-up ads. They may show up on your desktop or in programs, websites, or apps that didn’t have them before.
Spyware, also called grayware, is made to spy on you. It hides in the background, monitoring your computer usage and internet browsing activity. Spyware can harvest passwords, banking details, and emails and even log your keystrokes or change security settings. All of the information it gathers is sent to a remote user. Spyware can also be used to download and install other malicious applications without your permission.
Much like a biological virus, a computer virus will spread from host to host to infect as many devices as possible. Attached to files or programs, it can be spread through downloads, email, social media, or text messages.
However, a virus usually cannot infect a computer autonomously – it needs a user to run the program it is attached to. The harm caused by viruses ranges from minor annoyances like desktop wallpaper alterations to major system crashes or complete loss of data.
In comparison to viruses, worms can seem quite innocent, as they do not cause any direct damage to a system. A worm’s entire purpose is to copy itself and spread across a local drive or network.
Worms can also be paired with “payloads” designed to damage a system or extract information, but they don’t have to. The first worm, Creeper, simply notified infected users of its presence.
Trojan malware infiltrates computers by hiding in innocent-looking programs, like the Trojan horse of the Greek legend. Once it’s in, a Trojan can create backdoors for hackers to get into your system and collect your data or even completely lock you out of your computer. For example, the Zeus trojan collects data like victims’ keystrokes and credentials. Emotet was notorious for stealing data from individuals and companies alike.
Ransomware is one of the most serious cyber threats due to its ability to spread quickly and cause costly damage. Ransomware is designed to make a profit. Once the malware infects a machine, it encrypts all data, locking the user out. Then, it asks the victim to pay a ransom to decrypt the files.
Keylogging is the process of tracking the keys a user types to discover their sensitive passwords or monitor private communications. Different types of keyloggers exist, including ones based on stalkerware or hardware. This can make them very hard to discover as well.
How does NordVPN help?
How NordVPN can help depends on the malware you’re up against.
Protect your devices with NordVPN: Block malicious downloads, trackers, and ads.
Frequently asked questions
What is malware in simple terms?
Is malware a virus?
What is a good example of malware?
