Virus Hoaxes
Virus hoaxes are messages, usually sent by email, that amount to little more than chain letters. They pretend to alert you to the latest "undetectable" virus and simply waste your time and Internet bandwidth. The best course of action is to delete these hoaxes - they can cause genuine fear and alarm in the disabled, elderly and other vulnerable groups.
Spyware, Adware and Advertising Trojans
Spyware, Adware and Advertising Trojans are often installed with other programs, usually without your knowledge. They record your behaviour on the Internet, display targeted ads to you and can even download other malicious software on to your computer. They are often included within programs that you can download free from the Internet or that are on CDs given away free by magazines.
Spyware doesn’t usually carry viruses but it can use your system resources and slow down your Internet connection with the display of ads. If the Spyware contains bugs (faults) it can make your computer unstable but the main concern is your privacy. These programs record every step that you take on the Internet and forward it to an Ad Management Centre which reviews your searches and downloads to determine your shopping preferences. The Ad Management Centre will build up a detailed profile of you, without your knowledge, and can pass this on to third parties, again without your knowledge. Some Spyware can download more serious threats on to your computer, such as Trojan Horses.
Macro Viruses
Macros are simple programs that can be written to automate repetitive tasks in a document or make calculations in a spreadsheet. Macros can be written in documents created by Microsoft Word, in spreadsheets created by Microsoft Excel and in many other kinds of documents.
Macro viruses are malicious macro programs that are designed to replicate themselves from file to file and can cause damage to the files on your computer. They spread whenever you open an infected file.