A common misuse of the term viruses lately has been used to refer to malware or spyware programs. However, computer viruses are malicious programs which are created with the sole intent of disrupting the operation of a computer. Computer viruses are usually placed into computers without the permission or knowledge of the person who owns the computer, and can copy spread from one computer to another through the internet, CD’s, USB drives, floppies, messenger, or email.. A computer virus can cripple an entire computer system, damage files, or cause some minor or major annoyance problems to the computer owner.
Many people install anti-virus software to help proactively and reactionary detect and eliminate known infections, either when downloaded or executed.
There are several ways these anti-virus programs work, but most commonly is using a list of signature definitions; comparing the content of the computer’s memory and hard drive files to a database of known ‘signatures’. Although effective at removing and preventing damage from viruses which are already known, they are only as strong as their most recent definition update. The other method to use a mathematical algorithm to locate suspected activity based on common behaviors. This method allows newer software to detect new, undefined ones.
Viruses aren’t new. The first virus appeared on ARPANET back in the early 1970’s, infecting the TENEX operating system, making use of any connected modem to infect other systems. The first ‘in the wild’ virus was written back in 1982 for the Apple operating system. This was originally intended as a joke, attached to a game, which on the 50th play would then infect the user’s system. The first boot sector viruses started in the 80’s, and continued to proliferate into the wild through BBS’s and software sharing. Some viruses were written by software programmers themselves to thwart off software pirating with infecting systems. The 90’s brought us macro viruses which spread through popular office suites. Newer types of viruses focus on replication through instant messaging and advanced hiding techniques.
This is a list of some of the more popular versions of computer viruses:
Boot Sector Computer Viruses
The boot sector viruses become a whole lot popular in the eighties. This was when computer technology actually hit the mainstream. Quite like the name, boot sector viruses infect the boot sectors of a computer. These boot sectors are usually located in the bootable disk or in particular location in your computer hard drive. A number of these boot sector viruses in the past include names such as Disk Killer and others like Michelangelo. The damage caused by boot sector viruses can be devastating, varying from individual file loss to entire directories.
Companion Viruses
These sorts of viruses usually affect your computer by infecting your computers operating system. They work by creating a dangerous program that looks like the other valid files that are on your computer. These programs accompany other files that exist on your computer, so you may end up executing a virus instead of the program that you really wanted to run. These types of viruses can wait in memory for a program to run and can easily replicate.
Email Viruses
These sorts of viruses use e-mail in order to transmit viruses from one computer to the other. Someone may send you an e-mail that has an attachment that has a virus in it. When you open the attachment your computer gets infected. Some of them actually copy themselves to all the e-mail addresses in your address book and the virus gets to spread as quickly as it can. Avoid opening e-mails from anyone that you don’t know. Some e-mail programs actually now come with the capability to scan through attachments with antivirus programs. They can easily identify any virus programs before you would even spot them.
Macro Viruses
Macro viruses are small programs which can infect files created with certain applications, including word processing and spreadsheet office suites. These mini programs can take advantage of the program’s built in macro programming tools to perform maliciously.
Polymorphic Viruses
Polymorphic viruses actually will hide themselves each time they infect a system, making it nearly impossible to be detected by anti-virus string or signature searches. Because these types of viruses encrypt or encode themselves differently every time, they are more difficult to detect and are able to easily replicate large numbers of new instances of themselves.
Trojan horse viruses
Trojan horse viruses are actually malware, they are usually thought of as viruses because of the amount of damage that they can do to your computer. These viruses are actually quite tricky; they appear as something as innocuous as a screensaver or game. When you install the program you end up with a virus on your system. The virus may then leave a backdoor for hackers to enter into your computer. When these hackers enter they can then proceed to steal personal information such bank account and credit card information, passwords.
Worm Viruses
Worm Viruses have the ability to easily and quickly duplicate themselves, occupying tremendous amounts of computer resources while it wreaks havoc on your computer.
If you want to protect yourself from computer viruses such as the types listed above. It is absolutely essential that you obtain the best protection software available. Money need not be an obstacle for effective protection; there are many high quality free programs available. It’s important to make sure your anti-virus software is as up to date as possible, as new infections are discovered each day. You may also want to invest in a firewall that helps prevent other people accessing your computer. Once a computer is infected with a virus, it is unsafe to keep using this system; it can damage files and send to your contacts through email. You should also make regular backups of your data and keep this unconnected to your system, to restore your files if necessary.
