Computer viruses are those malicious programs that once they infect your computer, they will start causing mass destruction to your PC. Similar to biological viruses, they can multiply in various ways and develop from one type to another. Since there are hundreds of viruses out there, here are the five basic types of viruses that people are most likely to encounter, in order to make the identifying process easier.

• Trojan Virus

• Worms

• Macro Virus

• Boot Sector Virus

• File Infector Virus

Trojan Virus - This virus appears to be nothing more than an interesting computer program or file of a user who's interested in collecting audio files. Once this virus enters your computer, it doesn't reproduce, but instead makes your computer vulnerable to malicious intruders by allowing them to access and read your files. A Trojan horse must be sent by someone or carried by a program or software of some sort. The malicious functionality of a Trojan horse may be anything undesirable for a computer user, including data destruction or compromising a system by providing a means for another computer to gain access, thus bypassing normal access controls.

Worm – A Worm is a virus program that copies and multiplies itself by using computer networks and security flaws. Worms are more complex than Trojan viruses, I should say, and usually attacks multi-user systems. It can spread over corporate networks via the circulation of emails. Once multiplied, the copied worms scan the network for further escape and will then cause errors on the network.

Macro Virus - This type of virus usually comes as part of a document or spreadsheet, more often found in an email. Many of the current macro viruses are written in this language and attached to Word documents. This capability is powerful, but allows viruses to be written and executed much more easily than by using other methods.

Boot Sector Virus - A virus which attaches itself to the first part of the hard disk that is read by the computer upon start up, which are normally spread by floppy disks. In time, they can spread to other readable disks. Booting problems and start up problems, problems with retrieving data, computer performance instability and the inability to locate hard drives are all issues that may arise due to a boot sector virus infection.

File Infector Virus – As the name indicates, this type of virus was designed to avoid detection by antivirus software by changing itself internally. Upon running a program that has been corrupted by a file infector, the virus copies the malicious code and applies it to other executable applications on the computer. Files that are the most vulnerable to this type of infection have the extensions of EXE. and .COM, though any file is capable of execution can be infected.

How to fight some of these viruses is still completely a puzzle for anti-virus makers. However, knowing a little about your enemies could be an advantage to get vital information on how to defend your computer from those threats. Read on Virus Removal Help - How to Remove Viruses Easily From Your PC? in order to become more familiar with the steps on how to remove the common types of viruses from your computer.