In the search box on the right, type the terms "Trojan horse software", "Computer Worm" and "adware" and see what you can find out for yourself

Trojan software. This is an application that appears to do something useful such as a computer game (which is why you loaded it on to your computer in the first place) but quietly, behind the scenes it is doing something with ill-intent. A trojan may:-

• Log all your keystrokes and then send the details to a remote computer / server. Used to capture your passwords
• Allow someone else to take control of your computer whilst you are online.
• Capture screenshots and send them to a remote computer, once again with the intent of obtaining confidential information such as financial screenshots.

Worms. These are a bit like a computer virus but they spread on their own through compuer networks. Their biggest problem is the sheer amount of computer time and bandwidth they soak up, so making the network slow to a crawl.

Adware / Spyware: These are programs designed to keep track of which adverts you click on and then they send specific adverts to your browser. Fairly harmless but annoying and hard to get rid of.