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Its our job to know where they hide and how to remove all infected files. Not only your information can be stolen but also your computer can be compromised (used to spread the infected files) and slow your computer to a crawl.


About Malware includes Viruses, Worms, Trojans and Spyware

Short for "malicious software," malware refers to software programs designed to damage or do other unwanted actions on a computer system. In Spanish, "mal" is a prefix that means "bad," making the term "badware," which is a good way to remember it (even if you're not Spanish). Common examples of malware include viruses, worms, trojan horses, and spyware. Viruses, for example, can cause havoc on a computer's hard drive by deleting files or directory information. Spyware can gather data from a user's system without the user knowing it. This can include anything from the Web pages a user visits to personal information, such as credit card numbers.


Types of Viruses and Definitions

There are two major categories of viruses:

Boot Sector Viruses

Boot sector viruses infect the boot sector of a disk, therefore affecting the computer system during the start-up process. The boot sector is a small area on a disk which is read by the computer when it is turned on (booted). The most common way for a system to become infected is when an infected disk is left in the disk drive when the computer is being booted. The computer will read the virus from the boot sector and infect the entire system. These viruses are difficult to deal with because they are read during the start-up process even before the system is able to load its antivirus software to detect the virus.

File Infector Viruses

File infector viruses affect the program files that a system must load in order to make software function. The virus infects a file (usually files ending in ".COM" or ".EXE") by overwriting part of the program. By overwriting the program the virus replaces part of the program code with viral code. When the program is executed, the virus code is executed and it infects more files.

Here are some other types of viruses:

Memory Resident Viruses

These viruses hide in memory and are difficult to detect. When the virus is in memory it will infect any uninfected file that is executed. The only way to remove the virus is to turn the power of the infected computer off.

Non-memory Resident Viruses

These viruses infect files and are executed each time the infected file is executed. However, they do not reside in memory.

Multi-partite Viruses

Multi-partite viruses have characteristics of the boot strap virus and the file infector virus. They can infect .COM and .EXE files as well as the boot sector of diskettes and hard drives.

Stealth Viruses

Stealth viruses hide the changes that they've made in files or boot records so that antiviral programs can't detect them through these changes.

Polymorphic Viruses

Polymorphic viruses scramble their code each time they replicate so that none of its copies are the same. This makes it difficult for virus scanners to detect it because scanners search for a particular code.

Here is some research for viruses, trojans and worms.

Feel free to click on viruses from to get a full description.


Definition of Trojan

A program that appears legitimate, but performs some illicit activity when it is run. It may be used to locate password information or make the system more vulnerable to future entry or simply destroy programs or data on the hard disk. A Trojan is similar to a virus, except that it does not replicate itself. It stays in the computer doing its damage or allowing somebody from a remote site to take control of the computer. Trojans often sneak in attached to a free game or other utility. For information about various Trojans that are spread on the Internet.

The Trojan Horse
Trojan comes from Greek mythology, in which the Greeks battled the Trojans (people of Troy). After years of being unable to break into the fortified city, the Greeks built a wooden horse, filled it with soldiers and pretended to sail away. After the Trojans brought the horse into the city, the Greek soldiers crept out at night, opened the gates of Troy to the returning soldiers, and Troy was destroyed.