Security experts sounded the alarm in late 2021: Emotet is active again. Emotet spreads aggressive malware using emails. It enables criminals to break into millions of company computers worldwide to steal bank details, for example, or take networks hostage. How does malware work? And what can you do to protect yourself against it?
Malware is the collective name for different types of harmful software. Malware can take over your computer when you visit a hacked website, download illegal software, or open a harmful email attachment. Malware can be a virus, ransomware, a Trojan horse, or spyware (in Dutch).
A malware infection on your computer or other digital device can have a big impact. For example, criminals could steal your bank or computer login data, or access other privacy-sensitive information like your credit card number. Malware enables cybercriminals to deactivate your antivirus software from a distance. Your computer is no longer protected, and harmful software can enter your computer. Your computer could become part of a botnet (in Dutch): a network of computers, controlled by criminals, to spread phishing messages or execute DDoS attacks.
How to recognise malware
You may not realise that your computer has been infected by malware. These are signs that your computer may be infected:
- Your computer switches off at random, and you cannot reboot it.
- Your computer is slower than usual.
- Internet is slower than usual.
- Computer programs no longer work.
- Software you did not ask for was automatically installed on your computer.
Types of malwareThere are several types of malware. Here are the most common ones:
Adware is a combination of ‘advertising’ and ‘malware’. It displays unsolicited advertisements when you are browsing websites. The most common type of adware is an ad pop-up screen. If you are lucky, adware is simply annoying. But if you are unlucky, you click a harmful adware pop-up, that damages the security settings of your wifi network, for instance. That makes your network vulnerable and allows cybercriminals to break into your computer system.
Cybercriminals use ransomware to lock your computer files. You can no longer access or use them. The criminals then threaten to delete your files, unless you pay a ransom. They often demand a ransom in cryptocurrency, like bitcoin.
Ransomware enters your computer when you open a harmful file, for example, an email attachment. Or it comes in through a leak in your firewall, if you have failed to update your security software (in Dutch).
In that case, ransomware enters your computer without you even clicking on anything. Ransomware is also called cryptoware or hostage software.
This type of malware is named after the famous wooden horse used by Greek soldiers to enter Troy and open the city gates from within. A Trojan horse is a harmful software program that appears harmless. It is often sent as an email attachment, or hidden inside programs you download. The harmful program gives a hacker access to your computer. They can edit, copy, or delete hardware data from your computer, without you even noticing.
Spyware is a type of malware that enables cyber criminals to spy on you. They can see exactly what you are doing online, and steal your passwords and bank details to use for fraudulent purposes.
A computer virus is a dangerous software program that infects your computer. The virus can copy itself onto other files on your computer, and so spread to other computers. This does not happen automatically, you as the user of the infected computer spread the virus. For example, when you email a file you did not know was infected. When the recipient opens the infected file, the virus becomes active on their computer as well. A virus can greatly damage software and files on your computer. It can delete or distribute sensitive information.
A computer worm is a type of malware that infects computers and automatically spreads across your computer network. Unlike a virus, a worm does not have to be installed by a user. The worm uses security leaks and breaches in networks and operating systems to place harmful software. A computer worm usually enters via an email, a harmful link, or a contaminated USB stick.
Tips to fight malware
Stay ahead of cybercriminals, and protect your business against malware. You can take these measures:
- Do not download or install illegal software.
- Install antivirus software.
- Keep your software up to date (in Dutch).
- Do not click on links in emails or on websites you do not trust.
- Use an ad blocker.
- Back up your computer files regularly, and store your backups (in Dutch) in a safe, external place.
Protect your company from cybercrime
There is a host of tools you can use to protect your business from different types of cybercrime, such as malware. The Digital Trust Center (DTC) basic cyber resilience scan (only available in Dutch) helps you minimise the cyber risks in your company. Based on your replies, you receive feedback to help you improve your security. The Digital Trust Center was founded by the Ministry of Economic Affairs and Climate Policy, and it helps entrepreneurs to run their businesses in a digitally secure way.
Do you want to do more to ensure your company’s cybersecurity? Use these 5 tools for cyber resilience and read these tips to protect your business.
Was your business targeted by malware? We would like to get in touch. Share your experience via firstname.lastname@example.org.
Hacked, now what?
Were you hacked, or do you think you may have been? Find out what to do with these useful tips from the Digital Trust Center.