Most users will have encountered a computer parasite at some point in their lives. Many users refer to them simply as computer viruses. However, the term “virus” is inaccurately used in a lot of cases. What people usually mean when they say “virus” is malware (malicious software). Malware is an umbrella term that covers all kinds of computer threats, from adware and browser hijackers to ransomware and Trojans.

In many cases, knowing what exactly has infected your computer is essential to removing it successfully. Therefore, while you do not have to understand all the specifics, knowing the basics can go a long way towards keeping your computer safe. So if you are unfamiliar with the below terms, take a few minutes to read this article so that the next time your computer is infected, you know what you are dealing with.


It is a general term to refer to various malicious software programs. They include computer viruses, ransomware, worms, Trojan horses, rootkits, keyloggers, dialers, spyware, adware, rogue security software etc. Basically, all software programs that use your information or are installed without your permission.


Spyware is a kind of branch of malware. Spyware gathers information about users without their knowledge. It can be put into 4 main categories which include: system monitors, Trojans, adware and tracking cookies. Spyware and adware are similar to viruses in the sense that they can be considered malicious in nature, but unlike viruses and worms, spyware does not usually self-replicate.


Usually focuses on automatically rendered advertisements in order to generate revenue for its author. These advertisements are not wanted by the user, therefore it is treated as malware. Advertisement content includes pop-up ads, shortcuts to users’ desktops and toolbars. The difference between adware and other malware is that adware cannot cause the same amount of damage as Trojans, keyloggers and dialers.

Browser Hijacker

browser-hijackerSimilarly to other types of malware, browser hijackers perform changes without the user’s permission. A browser hijacker can replace the home page, error page or search page without the user’s consent. It is similar to adware because the hijacked page generates money by increasing its advertising revenue. It may be installed through drive-by downloads or with infected e-mail.

Rogue-Security-SoftwareRogue Security Software

Basically, rogue security software fraudulent programs that deceive and mislead users into paying money for fake or simulated removal of malware (it can also be regarded as a form of ransomware). Alternatively, it claims to get rid of malware, but instead introduces it to the computer. Rogue software often goes together with pop-up ads that are infected, and may lead to Trojans and other malicious software. These malware programs go together with one another and may lead to difficulties when removing. After installation, it may become very hard to remove this type of software, and could lead to full re-installation of the system.

pupPotentially Unwanted Application

A potentially unwanted application (later PUA) is a term used to describe application that, while not malicious, are generally considered unsuitable for business networks. PUA classifications are: dialer, non-malicious spyware, remote administration tools, hacking tools and adware. The fact that PUA uses adware and installs unwanted toolbars can make it similar to a browser hijacker.