I’m often asked what a computer virus is, how it’s different from a worm or Trojan horse, and how it gets into my computer. Please find below my article, which gives you a brief explanation of these terms and how easily they can infect your system.
What is a computer virus?
Computer viruses are annoying at best and can be extremely destructive at worst. A computer virus is a piece of code that can be attached to one of your files or programs, allowing it to spread to other computers and infect them as it goes. This causes damage to files, software, and hardware.
Computer viruses can vary in severity in the same way as an organic virus. With an organic virus, unless it is kept in complete isolation, it is usually spread through human interaction. The difference is that (aside from the obvious) a computer virus needs human interaction in order to spread, such as sending an email or sharing a file.
What is a worm?
Like a virus, a worm is designed to copy itself to computers, but the horror is that it does so automatically.
It does this by taking control of the features of a computer that transports files and information. Once in your system, they have the ability to replicate in large numbers, very quickly. One of the things they’re famous for is sending copies to everyone in their address book, and if the recipient doesn’t know it, they’ll do the same to yours.
They have the potential to cause heavy traffic, clog networks, and in extreme cases, slow down the entire Internet.
So if you are waiting twice as long for pages to load, this could be a possible cause.
What is a trojan?
Like the Trojan horse in Greek mythology, which appeared to be a gift but actually contained soldiers, Trojans appear to be useful software. Unfortunately, they often arrive as an email attachment, usually appearing to be from a legitimate source, but when opened, they lead a trail of destruction. They can also be present in free software you can download, so be careful!
What is malware?
Malware is a term used to describe “malicious software” programs. Things that fall under this are spyware, adware, and cookies.
What is spyware and adware?
It has been estimated that 90% of all computers on the Internet are infected with some form of spyware.
Spyware refers to programs that can use your Internet connection to send information, usually without your permission or knowledge, to another computer. The information that it then collects could be a record of your browsing habits. This can include things you’ve downloaded and even personal information like your name and address.
There are different types of spyware that perform different functions. Some can change your home page, producing pop-up personal ads, even if you’re not online, and can even hijack your browser, taking you to an unexpected site. Spyware that provides you with personalized advertisements is also known as adware.
Some free software or programs have spyware included. Some of the more legitimate programs mention in their terms and conditions that they can collect information, although most people don’t tend to read this. However, spyware does not have to come bundled with a program. It usually installs surreptitiously, often in the form of a pop-up or asking you to install a plugin to allow it to display the site properly. Spyware can use your computer’s local resources, such as processor power and memory, as well as some of your Internet bandwidth.
So if your computer:
- slows down to a snail’s pace
- if you click on a link to one site and end up on another site, because your browser has been hijacked,
- entered a search and received an unexpected result
- you receive pop-up ads that address you by name from a site you haven’t visited
- you click your home page and it takes you to a new site and when you try to switch back the same site appears again,
Then you have probably been infected with some kind of Malware.
