Malware is computer software specifically created for damaging a computer or a network. Malware is a blanket term for all programs that cause unwanted events in a computer or information system.

Adverse effects of malware?

If malware is successfully installed on your computer, online criminals may attempt to use your personal details for criminal purposes. They may also take over your computer and have it visit certain websites, send spam or do other things without your knowledge. The effects of malware may be anything from service interruptions of a few seconds to identity theft. Malware is also used for harvesting online banking IDs with the intent of gaining access to your bank account.

How is malware spread?

The best-known types of malware are viruses, worms and spyware. Viruses typically infect computers through e-mails, online downloads and instant messaging applications. Viruses are also spread through disks, CDs, DVDs and memory sticks. Malware may also be spread through bogus links or downloads that appear interesting to the user (advertisements or announcements of cash prizes won).

How does malware manifest itself?

Malware causes all sorts of problems with computer use. The computer may slow down, and surfing and e-mail may become difficult. Legitimate programs may be disrupted, and the machine may restart itself on its own. Data loss or alteration, changing of the browser home page and similar disruptions are also symptoms.

How to prevent the spreading of malware?

Update your operating system and software to the most recent versions. Activate automatic updates whenever possible. Always be careful of which sites you visit and what files you download online. Never trust strange e-mail messages. More importantly, never open them! Even messages from people you know may contain malware as links or attachments if their account has been hacked.

What to do if there is already malware on your computer?

If a malware program has managed to install itself on your computer, try to remove it as soon as possible. One way of eliminating malware is to reinstall the operating system. For further information on malware, visit the Finnish national computer security incident response team's (CERT-FI) website. Based at the Finnish Communications Regulatory Authority, CERT-FI's task is to promote security in the information society by preventing, observing and solving information security incidents and disseminating information on threats to information security.


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