Virus, Spy ware, ad ware, Worms, Malicious Codes, Scripts and Spam are the most dangerous computer programs that can be download to a computer if it is not protected properly. How these threats enter a computer? Let me explain it first. There are two ways to install a program. One is visible and the other is invisible. In invisible mode software can be installed in the background silently. You will be working and software will be installing in the background and all of the sudden you will see an icon i.e. shortcut to that software on your desktop or on the first page. In visible mode a program can actually be seen installing and showing progress.

Virus

Virus is also software, which can be used to destroy a computer’s operating system. When your computer gets a virus it can steal any information from it. It is a program that can do any job on your computer. I will explain it later. Virus is the number one source, which can do a lot of damage without your consent. A virus is a computer program used for different destructive purposes. Once your computer gets a virus it will spread inside it and will damage or corrupt files on your computer. Once it is inside your computer it communicates with the people who sent it to your computer. That means the source of this virus can do anything on your computer. Why you can’t see viruses when they are installed? When you install software on your computer you can see it as you follow step-by-step instructions. You use your computer for Internet, email or other jobs. All this is done with the help of different software like Internet explorer or windows etc. A virus is a software when installed on a computer, can do anything.

Spy ware

A spy ware is also a computer program, which can be downloaded to your computer without your permission. It searches your computer for different purposes like music, pictures, movies, passwords and email addresses. A spy ware can silently monitor all your computer activities and report it to the source that sent it. A spy ware is downloaded to your computer automatically.

Ad ware

Ad ware is another type of computer program, which is used to display advertisement on your computer. It is download the same way like spy ware. A virus is usually used to download ad ware on your computer. When a computer get an ad ware, popups will open automatically on a computer displaying different advertisements.

Worm, Malicious code and Script

Worms and malicious code are sent to slow down networks. Unlike viruses malicious codes installs itself automatically on your computer without your help. It’s a kind of virus. It cannot be controlled by anti virus program.

Spam

Spam is a kind of virus too, which you receive through emails. Every email program has the option to stop Spam. If setup properly, you can stop most of the Spam.

All these threats like viruses, spy ware, ad ware, mal ware and other are programs designed for specific purposes. They can enter a computer through different ways like transferring files from one computer to another, downloading, from USB flash drives, clicking on different links on websites, emails and other ways.