A computer virus is a program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. Viruses can also replicate themselves. All computer viruses are man-made. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt. An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.
Categories of viruses
Viruses are categorized on various statistics like invasion, behavior, inherited family of virus, affects and damages that a computer virus can cause to an attacked system. Earlier, viruses were bounded just to hamper PC performance, corrupting files, blue screen death of the PC and some else. But due to enormous use of Internet and its needs diversified, virus makers have also become more vibrant and intense.
Trojan is a destructive program that is programmed to masquerade as a benign application. Unlike viruses, Trojan horses do not replicate themselves but they can be just as destructive and uses various aliases for the same program. There are various kinds of trojans like Banking trojan, FTP trojan, Proxy trojan and DoS Trojan.
Spyware is similar to a Trojan horse virus which are embeded under the name of some other useful program. Thus, when user unwittingly install the spyware while installing something else. A common way to become a victim of spyware is to download certain peer-to-peer file swapping products that are available today. Spyware covertly gathers user information through the user’s Internet connection without his or her knowledge, usually for advertising purposes. Spyware applications are typically bundled as a hidden component of freeware or shareware programs that can be downloaded from the Internet; however, it should be noted that the majority of shareware and freeware applications do not come with spyware. Once installed, the spyware monitors user activity on the Internet and transmits that information in the background to someone else. Spyware can also gather information about e-mail addresses and even passwords and credit card numbers.
Adware is a common name accustomed to describe software that is certainly given for the user having advertisements embedded within the application. Adware is regarded as a legit alternative offered to consumers who don’t wish to pay for software purchases. There are several ad-supported programs, games or utilities which have been distributed as adware or particularly freeware packages. Today we’ve got progressively more software programmers who deliver their merchandise as bundled freeware known as adware until you register for its full version. If you install any adware, then you will be thoroughly prompting advertisements to register and get the full key to stop these ads.
But the main concern associated with these Adware is they are not always associated with legit software companies. Thus, many third party sponsors make use of adware to conceal their fake programs within it. Unfortunately, some applications that contain adware track your online surfing habits as a way to serve ads associated for you. When such adware gets to be intrusive like this, then it can be a major concern regarding privacy and security reasons.
Potentially unwanted program
PUP stands for Potentially unwanted program that is basically dropped inside the computer by the freeware or shareware software’s from the internet as a bundled component. PUP silently analyse user’s activities and interfere with the browsing. PUP will drop pop-ups notifying you continuously to download and buy their products for better browsing experience. It assures that you click on these links so that they can steal your money. You will start noticing that the webpages are taking more time to open than usual and not only, even the browsers crashes all of a sudden more frequently. Not only that, PUPs are extremely intrusive and may drop other threats to corrupt the computer badly.