What is malware?

Malware is an umbrella term for all malicious soft­ware, such as computer viruses, trojans, and spyware. Malware is a serious cyber security threat to both individual users and organizations.

Why is malware a serious threat to you?

Malware is a broad term that includes several types of soft­ware with one shared characteristic: they are designed to cause harm in the infected system. Online criminals spread malware to carry out cyber attacks. Although now­adays malware spreads mostly through the internet, malware has been used to cause harm long before most devices were online. Before the time of the internet, malware could be spread with floppy disks, for instance.

The goals of spreading malware range from stealing people’s personal information to hijacking the victim’s computer, and more. And it is not only desktop computers that are at risk of getting infected by malware. Mobile devices, such as smart­phones, are equally tempting targets for online criminals.

The biggest threats caused by malware include:

  • Stealing credit card information or money from your bank account
  • Stealing personal information for identity theft or black­mailing
  • Stealing pass­words and login credentials for account take­over
  • Locking your device or files and demanding ransom
  • Destroying files and wiping out data
  • Stealing sensitive personal photos
  • Gathering information about your work­place and its systems
  • Forcing your device to spread malware or spam to other users’ devices
  • Using your computer for mining crypto­currency
  • Spying on what web­sites you visit or what you type on your key­board
  • Using your device to carry out DDoS attacks as a part of a botnet

Different types of malicious soft­ware

Although the technology to fight against malware gets better, online criminals, hackers and state-funded entities are always looking to develop new forms of malicious soft­ware. Here are a few common types of malware to look out for.


Computer viruses are some of the most common and well-known malicious programs. They inject malicious code into another computer program — usually through some pre-existing security vulnerability within the program. The code gets to work once the infected program is executed. This may result in corrupting and wiping out the infected device’s memory or preventing it from starting up, and many other things.

Trojan horse virus

A trojan horse virus looks like a normal file or piece of soft­ware. In reality, it is a virus in disguise, looking to corrupt your files, steal confidential and sensitive data, or spy on what you do on your device. Trojan viruses can bring with them many different types of malware.


Online criminals use ransom­ware to encrypt the infected device’s files so they cannot be accessed by the user. The catch is that the victim has to pay a ransom if they want to get their files back. Online criminals prefer crypto­currencies, such as bitcoin, for the payment of ransom, as they are more difficult to track. There is no guarantee that you get your files back by paying the ransom. The payment only encourages criminals and can be used to fund organized crime and terrorism. Contact your local authorities instead of paying.


Spyware is used to steal different kinds of data from your device and keep track of what you do. The goal of spyware is to do its work quietly in the back­ground without the user ever noticing its presence. So-called key­loggers are able to track what you type on your computer key­board to steal pass­words and login credentials. Spyware can also be used to record your screen to capture other information for carrying out identity theft and account take­over, for example.

Computer worms

Worms are especially hard to deal with as they are able to duplicate and spread from one device and network to another. To make matters worse, a worm can spread from one device to another even if the user does not do any­thing. The worm might be noticed only once it has spread enough to cause serious damage.

How to defend against malware?

Malicious soft­ware comes in different forms and you need to know how to defend your­self against them all. Some malware can be dealt with in particular ways, but there are some things you can do to improve your overall cyber security against them all. Here’s how you can better protect your­self against malware on all of your devices.

  • Use an anti­virus. An anti­virus program offers extensive protection for both your desktop computer and smart mobile devices.
  • Keep your device’s operating system and applications up to date. Always make sure to down­load the most recent official updates. In addition to adding new features, soft­ware updates fix bugs and plug holes that can be used by online criminals to hack into your device and spread malware.
  • Be careful which programs you down­load. Mobile devices are usually considered safe as applications are down­loaded and installed from the device’s official app store. You should still be wary of what you choose to down­load on your device.
  • Do not click suspicious links. Emails, text messages, posts on social media and web­sites can contain links to malicious web­sites and can make your device vulnerable to malware. Inspect URLs care­fully and never click them if they seem sketchy or are sent to you by some­one you don’t know. You may in fact be a target of a phishing attack.
  • Avoid inserting unknown hard drives into your computer. In addition to files down­loaded from the Internet, malware can spread from hard drives, CDs, USB sticks and other physical devices. Make sure not to plug unknown drives into your computer or allow someone you do not trust to connect their smart­phone or external hard drive.
  • Check what mobile apps and computer programs have access to. Many mobile apps require access to your phone’s camera, address book, location information, and saved files, for instance. Before granting access, think carefully if the program really needs access to every­thing.
  • Be careful when browsing in public. Public Wi‑Fi can be helpful when working remotely on the go or studying at a local cafe. Unfortunately, you cannot always be sure of the net­work’s safety. Avoid public Wi‑Fi if you can or use a VPN.
  • Use a fire­wall. A fire­wall acts as a filter between your device and the internet. It can protect you by stopping suspicious and potentially harmful network traffic. Although a fire­wall can stop hackers and viruses, it needs an anti­virus to back it up.

7 tips for identifying a malware infection

If your computer or mobile device is no longer working as it should or you have noticed some strange changes in it, there may be a piece of malware hiding on your device. Here are seven signs that can help detect malware.

  • Suspicious and unexpected pop-up windows
  • The device is working slower than it should
  • It takes longer than normal to start up or shut down
  • Unexplained increase in the use of data
  • The device and programs crash or freeze repeatedly
  • The battery of your device is drained faster than normally
  • Your device overheats for no apparent reason

All devices start slowing down as they age and can no longer maintain the charge of their battery as they used to. You should still make sure that the signs of aging are not in fact caused by malware. If you notice any of these signs, make sure to run a virus check on your device. This is an easy process with the help of advanced security soft­ware.

Stay protected online with F‑Secure Total

Vishing is just one trick in an online criminal’s tool­box for getting access to your private information or infecting your device with malware. That’s why you need to be protected on all of your devices.

F‑Secure Total helps you stay safe online, whether on your desk­top or mobile device. On top of an advanced anti­virus, Total comes with a VPN for safe and private browsing wherever you are, a pass­word manager and other tools for protecting your identity online. Try F‑Secure Total for free!

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