A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user. The original virus may modify the copies, or the copies may modify themselves, as occurs in a metamorphic virus. A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or the Internet, or by carrying it on a removable medium such as a floppy disk, CD, or USB drive. Additionally, viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer. Viruses are sometimes confused with computer worms and Trojan horses. A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a file that appears harmless until executed.

Many personal computers are now connected to the Internet and to local area networks, facilitating the spread of malicious code. Today's viruses may also take advantage of network services such as the World Wide Web and file sharing systems to spread, blurring the line between viruses and worms. Furthermore, some sources use an alternative terminology in which a virus is any form of self-replicating malware.

Some viruses are programmed to damage the computer by damaging programs, deleting files, or reformatting the hard disk. Others are not designed to do any damage, but simply replicate themselves and perhaps make their presence known by presenting text, video, or audio messages. Even these viruses can create problems for the computer user. They typically take up computer memory used by legitimate programs. As a result, they often cause erratic behavior and can result in system crashes. In addition, many viruses are bug-ridden, and these bugs may lead to system crashes and data loss.

source:http://en.wikipedia.org/wiki/Computer_virus

AVG ANTI-VIRUS FREE EDITION

This antiviral program offers rock-solid protection for no financial commitment. AVG Anti-Virus Free Edition provides all the necessities, including a tool for scanning your hard drive and e-mail, as well as a real-time shield to prevent infections. By default, the application is set to search for new virus definitions daily, but you always can use the scheduling tool to change this. Should a virus create serious system problems, AVG create a rescue disk to scan your computer in MS-DOS mode. The program doesn't tax your system when scanning or when running in the background and always proved effective in our tests. This app's interface can't be described as beautiful, yet it is mostly simple to navigate. Sure, you can plunk down a lot of cash for an antiviral application with more features, but AVG Anti-Virus Free Edition delivers the goods for free.

source:http://tech1.ipupdater.com/opencd/security.html

Spyware is computer software that is installed sealthly on a personal computer to intercept or take partial control over the user's interaction with the computer, without the user's informed consent.

While the term spyware suggests software that secretly monitors the user's behavior, the functions of spyware extend well beyond simple monitoring. Spyware programs can collect various types of personal information, but can also interfere with user control of the computer in other ways, such as installing additional software, redirecting Web browser activity, or diverting advertising revenue to a third party. In an attempt to increase the understanding of spyware, a more formal classification of its included software types is captured under the term privacy-invasive software.

In response to the emergence of spyware, a small industry has sprung up dealing in anti-spyware software. Running anti-spyware software has become a widely recognized element of computer security best practices for Microsoft Windows desktop computers. A number of jurisdictions have passed anti-spyware laws, which usually target any software that is sealthly installed to control a user's computer.

 

source:http://en.wikipedia.org/wiki/Spyware

 

Spyware Blaster

Despite the multiple tabs and variety of options, this utility maintains focus on its sole task: keeping ActiveX-based spyware from hijacking Internet Explorer and Mozilla. Wrapped in a no-frills yet good-looking tabbed interface, SpywareBlaster is easy to both navigate and operate. Additional features include the ability to disable Flash animations, create a block list of troublesome DLLs, take a snapshot of your system, and add customized ActiveX blockers for files not included in the program's database. Like most adware-removal programs, it lets you download the latest malware updates. We would have liked support for other popular browsers, such as Opera, and the program offers little help for PCs already infected with adware. Still, SpywareBlaster proves a helpful preventative addition to any antiadware arsenal.

source:http://tech1.ipupdater.com/opencd/security.html