Malware - Everything You Ever Wanted to Know But Were Too Scared to Ask

Malicious software, ormalwarefor short, is a general name for software that has been designed with evil intent. It includes viruses, worms, backdoors, ransomware, rootkits, key-loggers, adware, spyware, and Trojan horses, among other malicious programs... all the horrors of the internet.

It comes in many forms to disrupt your enjoyment of computing and surfing the web. Malware causes computers to slow-down, perform badly or crash. It is used to spy on you while you are using the internet, or to steal details of your bank accounts and credit cards. In other words, it interrupts lives and causes massive financial losses.

Malware is not the same asdefective software, which is legitimate software that contains harmful bugs or errors that were not corrected before the software was issued.
Experts estimate that more malware than legitimate software is currently being created.

Types of malware Here's a brief overview of the most common kinds of malware. Acomputervirusis a program that infects executable software (i.e. software in which the name ends in .exe) such as an app. A virus cannot spread until the software in which it is hiding is activated, i.e. you only get a virus in your computer when you do something, such as open a file or email.

Most viruses are harmful. A virus will take up space on your hard disk or use up processing time, access your private information, corrupt data, spam your contacts with copies of itself or log your keystrokes. Viruses cause billions of Euros worth of economic damage each year.

Awormis a standalone program that actively transmits itself to other computers. Unlike a virus, a worm spreads automatically and does not depend on you opening a file or email.

Worms almost always harm your computer or network, if only by consuming bandwidth and increasing network traffic. Many also contain extremely dangerous code. They might, for example, delete files in your computer (e.g. the ExploreZip worm), encrypt files so that you can't open them and have to pay a ransom to regain access, or send documents via e-mail.

Worms often install a backdoor in the infected computer. A back door enables its creator to get illegal access to your computer from a remote location while remaining undetected. Using a backdoor, the author of the worm can turn your computer into a zombie. Azombie computeris one that is under the control of the person who created the worm. These can be linked together to formBotnets, i.e. networks of zombie computers.

Botnetscan be used for many malicious purposes. They are, for example, used by spammers to send junk email or store contraband products such as child pornography. They can also be used to launch denial-of-service attacks.

Denial-of-service (DOS) attacksuse botnets that link thousands of zombie computers to attack government information websites, internet banking sites, credit card payment gateways and even internet service providers. The target website is bombed by the network of zombies, all at the same time, with so many bogus requests that it is overwhelmed and is inaccessible to legitimate traffic. Your computer could be one of the zombies. If it is, you'll notice that it has slowed down quite a bit.

Ransomware(akascareware) is malware that restricts access to your computer and demands a ransom for the restriction to be removed. The Ukash or Gárda Síochána virus which is currently attacking computers in Ireland is a prime example of ransomware. Arootkitis a sneaky type of malicious software that is installed in the root (where it is very difficult to detect) and that gives its creator full control over a system. Therootis the top directory of a computer, i.e. the innermost part of the file system. Once a rootkit is installed, the attacker can modify the existing software, including the software that used to detect or get rid of it. This makes detecting a rootkit is difficult. It also means that removal can be practically impossible, and reinstalling the operating system may be the only solution.

Key-logging(akakeystroke loggingorkeyboard capturing) is recording (logging) the keys struck on a keyboard, usually in such a way that the user is unaware that their actions are being monitored.

Key-logging has legitimate uses in studies of the interactions between computers and humans, and in checking how employees are using computers at work. But it can be used to copy passwords and personal identification numbers (PINs) in order to steal money from bank accounts and credit cards.

Adware is software that shows advertisements automatically. Adware may be designed to analyse the sites you visit and to show ads related to the goods and services you seem to like. Having ads popping up every few seconds on your screen can be extremely annoying.