I have been asked about security software. In the book I state that to guard against viruses and other malware you will need to have anti-virus software and that you will need a firewall. There are a number of excellent products on the market, for example these from Norton. Note that I am not recommending these products; you will need to shop around, scan the web and ask advice from experts based on your personal use of a computer. There are also excellent products from companies such as McAfee and Kaspersky so it’s your choice. What is certain is that if you don’t employ such products you are asking for trouble.