What is Malware?
Malware is a term used to describe malicious software that is designed to disrupt normal computer operation, gather personal information, gain unauthorized access to system resources and exhibit other unwanted activity. Some of the most common forms of malware are as follows:
A virus is a computer program or a code that attaches itself to a “host” program on one computer. It then replicates itself and attempts to transfer itself to another computer. Each time the infected host program runs, the virus runs too and it is able to further reproduce, attaching to other programs or causing other computer issues. A virus can be transmitted through files as well as through e-mails. An e-mail virus attaches itself to e-mail messages and often automatically sends itself to contacts in the victim’s address book. Some e-mail viruses launch when you view the infected message in the preview pane of your e-mail, while others require you to open the attachment
A trojan (also called a trojan horse) is a harmful program that appears to be a helpful one. For example, a trojan may appear as a pop-up stating that your computer has been infected by a virus and may invite the user to click the pop-up to remove it. In this case, clicking the pop-up would activate the virus on your computer. A trojan opens a backdoor into your computer allowing the attacker to do just about anything.
A worm is a stand-alone program that uses computer networks, USB drives, e-mails and other security vulnerabilities to replicate itself. It uses the network to find other machines that have a security hole and copies itself to the other machine.
Spyware is a type of malware that installs itself on a computer and collects information about the user without their knowledge. Spyware can use keystroke logging techniques to collect passwords you enter, your bank account numbers and PINs, your credit card numbers, and other personal information. This type of identity theft can be costly and very time consuming to rectify. Spyware can dramatically slow your computer, cause pop-ups or inappropriate site redirection in your web browser, block you from performing certain actions, or just cause general malfunctioning of software on your computer. Detecting and removing spyware helps you avoid these problems and keeps your computer running properly and efficiently.
Adware, a related category of software to spyware, may cause pop-up advertisements to appear on your screen, change your home page, disrupt your network access, and reduce the stability and usability of your system.
Warning: Watch out for fake virus alerts
A few of the other programs that are referred to as “rogue security software” claim to remove spyware but are themselves spyware. Never install “spyware-removal” software that you see advertised on pop-up windows without checking it out first. Learn more about rogue security software.