Viruses and Spyware - A guide for learners

Viruses and Spyware:
Ranging from simple and almost amusing annoyance to malicious intention and devious collection of personal information, Viruses and Spyware in all their incarnations are a real and constant threat on the internet today.
Viruses:
Viruses are the easier to handle and prevent of the two. Viruses come under several major categories:
Worms.
These are viruses that propagate almost completely without human intervention, by taking advantage of vulnerabilities in system security. Worms are usually very small, and as such, do not cause any specific harm. Their payload of annoying is usually a consequence of their existence. For example, they may overload networks by flooding them with transferring instances of themselves, they may cause a Denial of Service by forcing servers perform long and ultimately useless operations, or they may crash Windows components, causing shutdowns or reboots. Trojans.
Not viruses in the classic sense, Trojans are programs that once installed on a host system, open up a back door server, allowing a malicious user to gain control of the system. Trojans are almost always distributed as part of another piece of software, or sometimes as a misdirection trick. Typically, a Trojan does not harm the infected computer itself, but by opening a port, allows the individual who programmed the Trojan to gain access to your files and do anything they please. Usually however, Trojans are used as part of botnets; large groupings of infected hosts used as a flooding weapon. Others.
Yes, itÃ¢â‚¬â„¢s not a particularly scientific term, but there are so many hundreds of thousands of viruses out there that exist simply to slow your computer to a grinding half, crash randomly, delete files, attack antivirus software and basically make a nuisance of themselves, categorizing them could take an eon.
Generally, viruses are propagated by internet users with inadequate virus protection, out of date software and unsafe browsing/emailing habits. Infection is easily avoided by the savvy individual. You can be kept clean of infection by following these guidelines.
Keep your virus software and pattern definitions up to date. This significantly reduces the chances of infection as new viruses are continuously identified. It is not unusual for pattern updates to be available every couple of days. Run regular virus scans of your hard drives. Combined with regular pattern updates, this neutralizes any viruses that managed to sneak through before pattern updates were available and stops you from passing the viruses onto friends and colleagues. Make sure software is up to date, especially Windows and Internet Explorer. Mistakes in software programming allow malicious users to develop exploits, opening holes for virus infection. These mistakes are continuously found and fixed, and in the case of Microsoft software, patches are available through Windows Update. Do not open email attachments from addresses that are not known to you. These include emails purporting to be from you, returned due to error. Many virus scanners monitor incoming email, but viruses can be re-packed to disguise their content. Some viruses actively attack antivirus software, rendering it non-functional or preventing pattern updates. If you suspect you have such an infection, bring in your computer for service immediately, to stamp the virus out before it can spread.
_____________________________________________________
Spyware::
Spyware is a more difficult threat, simply due to its lack of exposure and level of user awareness. Unlike viruses, which have only destructive or malicious purposes, Spyware is often installed unawares and completely legally, right before a userÃ¢â‚¬â„¢s eyes. Many small programs and utilities available for download that offer simple services such as improved or convenient web searching, system clock synchronization or localized weather reporting are actually designed to collect information such as where or how you browse on the internet and send the information back to analysts for marketing purposes. Aside from privacy concerns, these programs are usually poorly designed, and take up excessive quantities of your internet bandwidth and system resources. Other Spyware threats are installed through Web applications, issued in exchange for access to a website, or games.

Some very popular software suits such as Kazaa Media Desktop and DivX 5 Pro are clearly marked as Spyware Subsidised. The most noteworthy threats are Spyware programs that attack other Spyware programs, including those that claim to remove Spyware, but are actually Spyware themselves. The following guidelines should help you to avoid Spyware infection.
Use a well known anti-Spyware software, such as Ad-Aware (), Spybot () or Microsoft Anti Spyware (); any one of those will do. Be a little cynical. Although free software is widespread (some of the best software available is free in fact), Spyware takes advantage of human greed. As mentioned before, two of the most widespread infections are installed by Kazaa, a file sharing program used to obtain free music, and DivX, used to play and encode high quality downloadable movies. Be aware of fake dialog boxes that are actually imbedded pictures in your browser. Some instruct you to turn off built in Windows XP Service Pack 2 security, or to enable or download an unsafe web application. Do so only at your peril. Some Spyware actively attacks or evades anti-Spyware software, making it very difficult to remove. If you suspect you have such an infection, you may need professional assistance. Be aware however, that removing infections can be very difficult. There are many technicians out there who will simply want to reinstall Windows, because they are unable to, or unwilling to spend the time, removing your infection.